DTE Energy (DTE) 10-Q 28 Oct 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2019shares
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	1-11607
Entity Registrant Name	DTE Energy Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-3217752
Entity Address, Address Line One	One Energy Plaza
Entity Address, City or Town	Detroit
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48226-1279
City Area Code	313
Local Phone Number	235-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	183,396,510
Entity Central Index Key	0000936340
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
DTE Electric
Entity File Number	1-2198
Entity Registrant Name	DTE Electric Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-0478650
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	138,632,324
Entity Central Index Key	0000028385
Common stock, without par value
Title of 12(b) Security	Common stock, without par value
Trading Symbol	DTE
Security Exchange Name	NYSE
2012 Series C 5.25% Junior Subordinated Debentures due 2062
Title of 12(b) Security	2012 Series C 5.25% Junior Subordinated Debentures due 2062
Trading Symbol	DTQ
Security Exchange Name	NYSE
2016 Series B 5.375% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series B 5.375% Junior Subordinated Debentures due 2076
Trading Symbol	DTJ
Security Exchange Name	NYSE
2016 Series F 6.00% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series F 6.00% Junior Subordinated Debentures due 2076
Trading Symbol	DTY
Security Exchange Name	NYSE
2017 Series E 5.25% Junior Subordinated Debentures due 2077
Title of 12(b) Security	2017 Series E 5.25% Junior Subordinated Debentures due 2077
Trading Symbol	DTW
Security Exchange Name	NYSE

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating Revenues
Utility operations	$ 1,656	$ 1,669	$ 4,937	$ 4,923
Non-utility operations	1,463	1,881	4,584	5,539
Operating Revenues	3,119	3,550	9,521	10,462
Operating Expenses
Fuel, purchased power, and gas — utility	400	453	1,342	1,440
Fuel, purchased power, and gas — non-utility	1,257	1,682	3,900	4,898
Operation and maintenance	588	604	1,739	1,721
Depreciation and amortization	322	273	923	826
Taxes other than income	101	99	311	307
Asset (gains) losses and impairments, net	1	10	14	8
Operating Expenses	2,669	3,121	8,229	9,200
Operating Income	450	429	1,292	1,262
Other (Income) and Deductions
Interest expense	162	142	468	412
Interest income	(4)	(3)	(11)	(9)
Non-operating retirement benefits, net	9	9	28	27
Other income	(98)	(99)	(259)	(262)
Other expenses	17	11	40	51
Other (Income) and Deductions	86	60	266	219
Income Before Income Taxes	364	369	1,026	1,043
Income Tax Expense	47	34	122	121
Net Income	317	335	904	922
Less: Net Income (Loss) Attributable to Noncontrolling Interests	(2)	1	2	(7)
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 319	$ 334	$ 902	$ 929
Basic Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 1.74	$ 1.84	$ 4.93	$ 5.13
Diluted Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 1.73	$ 1.84	$ 4.91	$ 5.13
Weighted Average Common Shares Outstanding
Basic (in shares)	183	182	183	181
Diluted (in shares)	184	182	184	181
DTE Electric
Operating Revenues
Utility operations	$ 1,519	$ 1,521	$ 3,944	$ 4,002
Operating Expenses
Fuel, purchased power, and gas — utility	399	438	1,067	1,163
Operation and maintenance	356	360	1,048	1,025
Depreciation and amortization	244	202	694	616
Taxes other than income	80	77	233	232
Asset (gains) losses and impairments, net	0	0	13	0
Operating Expenses	1,079	1,077	3,055	3,036
Operating Income	440	444	889	966
Other (Income) and Deductions
Interest expense	80	73	234	210
Interest income	0	0	(1)	0
Non-operating retirement benefits, net	0	(1)	0	(1)
Other income	(20)	(23)	(78)	(72)
Other expenses	14	9	34	49
Other (Income) and Deductions	74	58	189	186
Income Before Income Taxes	366	386	700	780
Income Tax Expense	59	81	113	172
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 307	$ 305	$ 587	$ 608

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Income	$ 317	$ 335	$ 904	$ 922
Net Income	319	334	902	929
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes of $2, $—, $4 and $2, respectively	4	2	11	7
Net unrealized gains (losses) on derivatives during the period, net of taxes of $(1), $—, $(4), and $—, respectively	(4)		(13)
Net unrealized gains (losses) on derivatives during the period, net of taxes of $(1), $—, $(4), and $—, respectively		1		1
Foreign currency translation	0	0	1	(1)
Other comprehensive income (loss)	0	3	(1)	7
Comprehensive income	317	338	903	929
Less: Comprehensive income (loss) attributable to noncontrolling interests	(2)	1	2	(7)
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	319	337	901	936
DTE Electric
Net Income	307	305	587	608
Other comprehensive income (loss), net of tax:
Other comprehensive income (loss)	0	0	0	0
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	$ 307	$ 305	$ 587	$ 608

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Tax effect on benefit obligation	$ 2	$ 0	$ 4	$ 2
Tax effect on net unrealized losses on derivatives during the period	$ (1)		$ (4)
Tax effect on net unrealized losses on derivatives during the period		$ 0		$ 0

Consolidated Statements of Fina

Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 76	$ 71
Restricted cash	0	5
Accounts receivable (less allowance for doubtful accounts)
Customer	1,453	1,789
Other	264	108
Inventories
Fuel and gas	413	406
Materials and supplies	393	405
Derivative assets	75	102
Regulatory assets	22	153
Prepaid property tax	153	70
Other	136	151
Total Current Assets	2,985	3,260
Investments
Nuclear decommissioning trust funds	1,577	1,378
Investments in equity method investees	1,839	1,771
Other	253	219
Total Investments	3,669	3,368
Property
Property, plant, and equipment	33,473	31,810
Accumulated depreciation and amortization	(9,715)	(10,160)
Property, plant, and equipment, net	23,758	21,650
Other Assets
Goodwill	2,293	2,293
Regulatory assets	4,057	4,568
Intangible assets	940	849
Notes receivable	193	64
Derivative assets	36	31
Prepaid postretirement costs	74	45
Operating lease right-of-use assets	145
Other	195	160
Total Other Assets	7,933	8,010
Total Assets	38,345	36,288
Accounts payable
Accounts payable	1,033	1,329
Accrued interest	153	127
Dividends payable	173	172
Short-term borrowings	724	609
Current portion long-term debt, including finance leases	1,206	1,499
Derivative liabilities	68	67
Regulatory liabilities	55	126
Short-term borrowings
Operating lease liabilities	34
Other	419	509
Total Current Liabilities	3,865	4,438
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	12,708	10,982
Junior subordinated debentures	1,146	1,145
Finance lease liabilities	4	7
Total Long-Term Debt (net of current portion)	13,858	12,134
Other Liabilities
Deferred income taxes	2,257	1,975
Regulatory liabilities	3,313	2,922
Asset retirement obligations	2,576	2,469
Unamortized investment tax credit	163	138
Derivative liabilities	74	89
Accrued pension liability	658	837
Nuclear decommissioning	235	205
Operating lease liabilities	105
Other	337	364
Total Other Liabilities	9,718	8,999
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	4,370	4,245
Retained earnings	6,516	6,112
Accumulated other comprehensive loss	(146)	(120)
Total DTE Energy/DTE Electric Company Equity	10,740	10,237
Noncontrolling interests	164	480
Total Equity	10,904	10,717
Total Liabilities and Equity	38,345	36,288
DTE Electric
Current Assets
Cash and cash equivalents	26	18
Accounts receivable (less allowance for doubtful accounts)
Customer	779	750
Affiliates	1	11
Other	62	54
Inventories
Fuel and gas	180	171
Materials and supplies	284	279
Regulatory assets	22	148
Prepaid property tax	116	47
Other	35	42
Total Current Assets	1,505	1,520
Investments
Nuclear decommissioning trust funds	1,577	1,378
Other	36	34
Total Investments	1,613	1,412
Property
Property, plant, and equipment	23,917	22,747
Accumulated depreciation and amortization	(6,697)	(7,310)
Property, plant, and equipment, net	17,220	15,437
Other Assets
Regulatory assets	3,340	3,829
Intangible assets	21	21
Prepaid postretirement costs — affiliates	189	189
Operating lease right-of-use assets	64
Other	159	121
Total Other Assets	3,773	4,160
Total Assets	24,111	22,529
Accounts payable
Affiliates	81	71
Other	403	441
Accrued interest	81	74
Current portion long-term debt, including finance leases	336	4
Regulatory liabilities	28	98
Short-term borrowings
Affiliates	97	101
Other	382	149
Operating lease liabilities	13
Other	154	139
Total Current Liabilities	1,575	1,077
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	6,847	6,538
Finance lease liabilities	4	7
Total Long-Term Debt (net of current portion)	6,851	6,545
Other Liabilities
Deferred income taxes	2,311	2,246
Regulatory liabilities	2,606	2,171
Asset retirement obligations	2,361	2,271
Unamortized investment tax credit	162	137
Nuclear decommissioning	235	205
Accrued pension liability — affiliates	611	718
Accrued postretirement liability — affiliates	262	278
Operating lease liabilities	45
Other	82	88
Total Other Liabilities	8,675	8,114
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	4,631	4,631
Retained earnings	2,379	2,162
Total DTE Energy/DTE Electric Company Equity	7,010	6,793
Total Liabilities and Equity	$ 24,111	$ 22,529

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Allowance for doubtful accounts	$ 93	$ 91
Shareholder’s Equity
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	183,396,510	181,925,281
Common stock, shares outstanding (in shares)	183,396,510	181,925,281
DTE Electric
Allowance for doubtful accounts	$ 48	$ 53
Shareholder’s Equity
Par value (in dollars per share)	$ 10	$ 10
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	138,632,324	138,632,324
Common stock, shares outstanding (in shares)	138,632,324	138,632,324

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net Income	$ 904	$ 922
Net Income	902	929
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	923	826
Nuclear fuel amortization	45	39
Allowance for equity funds used during construction	(18)	(20)
Deferred income taxes	285	118
Equity earnings of equity method investees	(77)	(99)
Dividends from equity method investees	129	48
Asset (gains) losses and impairments, net	14	11
Changes in assets and liabilities:
Accounts receivable, net	188	85
Inventories	5	11
Prepaid postretirement benefit costs	(29)	(45)
Accounts payable	(291)	9
Accrued pension liability	(179)	(205)
Accrued postretirement liability	0	(61)
Derivative assets and liabilities	8	24
Regulatory assets and liabilities	203	283
Other current and noncurrent assets and liabilities	(209)	101
Net cash from operating activities	1,901	2,047
Investing Activities
Plant and equipment expenditures — utility	(1,982)	(1,562)
Plant and equipment expenditures — non-utility	(177)	(217)
Acquisition, net of cash acquired	(174)	0
Notes receivable	(81)	0
Proceeds from sale of nuclear decommissioning trust fund assets	594	810
Investment in nuclear decommissioning trust funds	(599)	(810)
Distributions from equity method investees	9	8
Contributions to equity method investees	(128)	(545)
Other	(20)	(20)
Net cash used for investing activities	(2,558)	(2,336)
Financing Activities
Issuance of long-term debt, net of issuance costs	1,433	1,433
Redemption of long-term debt	0	(105)
Short-term borrowings, net	115
Short-term borrowings, net		(544)
Issuance of common stock	0	7
Dividends paid on common stock	(518)	(459)
Contributions from noncontrolling interests, principally REF entities	23	43
Distributions to noncontrolling interests	(44)	(31)
Purchases of noncontrolling interest, principally SGG	(300)	0
Other	(52)	(40)
Net cash from financing activities	657	304
Net Increase (Decrease) in Cash and Cash Equivalents	0	15
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	76	89
Cash, Cash Equivalents, and Restricted Cash at End of Period	76	104
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	292	275
DTE Electric
Operating Activities
Net Income	587	608
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	694	616
Nuclear fuel amortization	45	39
Allowance for equity funds used during construction	(17)	(14)
Deferred income taxes	66	156
Asset (gains) losses and impairments, net	13	0
Changes in assets and liabilities:
Accounts receivable, net	(20)	(89)
Inventories	(14)	43
Accounts payable	(15)	18
Accrued pension liability — affiliates	(107)	(185)
Accrued postretirement liability — affiliates	(16)	(71)
Regulatory assets and liabilities	178	195
Other current and noncurrent assets and liabilities	(237)	(71)
Net cash from operating activities	1,157	1,245
Investing Activities
Plant and equipment expenditures	(1,611)	(1,248)
Proceeds from sale of nuclear decommissioning trust fund assets	594	810
Investment in nuclear decommissioning trust funds	(599)	(810)
Other	(19)	(7)
Net cash used for investing activities	(1,635)	(1,255)
Financing Activities
Issuance of long-term debt, net of issuance costs	643	520
Short-term borrowings, net — affiliate	(4)	27
Short-term borrowings, net — other	233	(187)
Dividends paid on common stock	(370)	(346)
Other	(16)	(7)
Net cash from financing activities	486	7
Net Increase (Decrease) in Cash and Cash Equivalents	8	(3)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	18	15
Cash, Cash Equivalents, and Restricted Cash at End of Period	26	12
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	$ 168	$ 152

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	DTE Electric	DTE ElectricCommon Stock	DTE ElectricAdditional Paid-in Capital	DTE ElectricRetained Earnings	DTE ElectricAccumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Dec. 31, 2017		179,387,000					138,632,000
Beginning Balance at Dec. 31, 2017	$ 9,990	$ 3,989	$ 5,643	$ (120)	$ 478
Beginning Balance at Dec. 31, 2017						$ 6,265	$ 1,386	$ 2,920	$ 1,956	$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income						140			140
Net Income (Loss)	351		361		(10)
Dividends declared on common stock	(160)		(160)			(115)			(115)
Contribution of common stock to pension plan (in shares)		1,751,000
Contribution of common stock to pension plan	175	$ 175
Other comprehensive income (loss), net of tax	2			2
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		345,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	5	$ (1)	(1)		7
Ending Balance (in shares) at Mar. 31, 2018		181,483,000					138,632,000
Ending Balance at Mar. 31, 2018	10,363	$ 4,163	5,848	(123)	475
Ending Balance at Mar. 31, 2018						6,290	$ 1,386	2,920	1,984	0
Beginning Balance (in shares) at Dec. 31, 2017		179,387,000					138,632,000
Beginning Balance at Dec. 31, 2017	9,990	$ 3,989	5,643	(120)	478
Beginning Balance at Dec. 31, 2017						6,265	$ 1,386	2,920	1,956	3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	929					608
Net Income (Loss)	922
Other comprehensive income (loss), net of tax	7					0
Ending Balance (in shares) at Sep. 30, 2018		181,925,000					138,632,000
Ending Balance at Sep. 30, 2018	10,690	$ 4,232	6,093	(118)	483
Ending Balance at Sep. 30, 2018						6,527	$ 1,386	2,920	2,221	0
Beginning Balance (in shares) at Mar. 31, 2018		181,483,000					138,632,000
Beginning Balance at Mar. 31, 2018	10,363	$ 4,163	5,848	(123)	475
Beginning Balance at Mar. 31, 2018						6,290	$ 1,386	2,920	1,984	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income						163			163
Net Income (Loss)	236		234		2
Dividends declared on common stock	(321)		(321)			(115)			(115)
Issuance of common stock (in shares)		160,000
Issuance of common stock	16	$ 16
Other comprehensive income (loss), net of tax	2			2
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		130,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	22	$ 26	(1)		(3)
Ending Balance (in shares) at Jun. 30, 2018		181,773,000					138,632,000
Ending Balance at Jun. 30, 2018	10,318	$ 4,205	5,760	(121)	474
Ending Balance at Jun. 30, 2018						6,338	$ 1,386	2,920	2,032	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	334					305			305
Net Income (Loss)	335		334		1
Dividends declared on common stock						(116)			(116)
Issuance of common stock (in shares)		95,000
Issuance of common stock	10	$ 10
Other comprehensive income (loss), net of tax	3			3		0
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		57,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	24	$ 17	(1)		8
Ending Balance (in shares) at Sep. 30, 2018		181,925,000					138,632,000
Ending Balance at Sep. 30, 2018	$ 10,690	$ 4,232	6,093	(118)	483
Ending Balance at Sep. 30, 2018						$ 6,527	$ 1,386	2,920	2,221	$ 0
Beginning Balance (in shares) at Dec. 31, 2018	181,925,281	181,925,000				138,632,324	138,632,000
Beginning Balance at Dec. 31, 2018	$ 10,717	$ 4,245	6,112	(120)	480
Beginning Balance at Dec. 31, 2018	10,237					$ 6,793	$ 1,386	3,245	2,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income						147			147
Net Income (Loss)	408		401		7
Dividends declared on common stock	(173)		(173)			(124)			(124)
Contribution of common stock to pension plan (in shares)		815,000
Contribution of common stock to pension plan	100	$ 100
Other comprehensive income (loss), net of tax	2			2
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		472,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	(34)	$ (21)	(1)		(12)
Ending Balance (in shares) at Mar. 31, 2019		183,212,000					138,632,000
Ending Balance at Mar. 31, 2019	$ 11,020	$ 4,324	6,364	(143)	475
Ending Balance at Mar. 31, 2019						$ 6,816	$ 1,386	3,245	2,185
Beginning Balance (in shares) at Dec. 31, 2018	181,925,281	181,925,000				138,632,324	138,632,000
Beginning Balance at Dec. 31, 2018	$ 10,717	$ 4,245	6,112	(120)	480
Beginning Balance at Dec. 31, 2018	10,237					$ 6,793	$ 1,386	3,245	2,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	902					587
Net Income (Loss)	904
Other comprehensive income (loss), net of tax	$ (1)					$ 0
Ending Balance (in shares) at Sep. 30, 2019	183,396,510	183,397,000				138,632,324	138,632,000
Ending Balance at Sep. 30, 2019	$ 10,904	$ 4,370	6,516	(146)	164
Ending Balance at Sep. 30, 2019	10,740					$ 7,010	$ 1,386	3,245	2,379
Beginning Balance (in shares) at Mar. 31, 2019		183,212,000					138,632,000
Beginning Balance at Mar. 31, 2019	11,020	$ 4,324	6,364	(143)	475
Beginning Balance at Mar. 31, 2019						6,816	$ 1,386	3,245	2,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income						133			133
Net Income (Loss)	179		182		(3)
Dividends declared on common stock	(347)		(347)			(123)			(123)
Other comprehensive income (loss), net of tax	(3)			(3)
Purchase of noncontrolling interests, principally SGG	(300)	$ (3)			(297)
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		90,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	20	$ 23	(1)		(2)
Ending Balance (in shares) at Jun. 30, 2019		183,302,000					138,632,000
Ending Balance at Jun. 30, 2019	10,569	$ 4,344	6,198	(146)	173
Ending Balance at Jun. 30, 2019						6,826	$ 1,386	3,245	2,195
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	319					307			307
Net Income (Loss)	317		319		(2)
Dividends declared on common stock						(123)			(123)
Other comprehensive income (loss), net of tax	0					$ 0
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)		95,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	$ 18	$ 26	(1)		(7)
Ending Balance (in shares) at Sep. 30, 2019	183,396,510	183,397,000				138,632,324	138,632,000
Ending Balance at Sep. 30, 2019	$ 10,904	$ 4,370	$ 6,516	$ (146)	$ 164
Ending Balance at Sep. 30, 2019	$ 10,740					$ 7,010	$ 1,386	$ 3,245	$ 2,379

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 1.89	$ 0.945	$ 1.77	$ 0.88

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	ORGANIZATION AND BASIS OF PRESENTATION Corporate Structure DTE Energy owns the following businesses: • DTE Electric is a public utility engaged in the generation, purchase, distribution, and sale of electricity to approximately 2.2 million customers in southeastern Michigan; • DTE Gas is a public utility engaged in the purchase, storage, transportation, distribution, and sale of natural gas to approximately 1.3 million customers throughout Michigan and the sale of storage and transportation capacity; and • Other businesses primarily involved in 1) services related to the gathering, transportation, and storage of natural gas; 2) power and industrial projects; and 3) energy marketing and trading operations. DTE Electric and DTE Gas are regulated by the MPSC. Certain activities of DTE Electric and DTE Gas, as well as various other aspects of businesses under DTE Energy, are regulated by the FERC. In addition, the Registrants are regulated by other federal and state regulatory agencies including the NRC, the EPA, EGLE, and for DTE Energy, the CFTC. Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2018 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions, include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2019 . The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself. Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation. Principles of Consolidation The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to significantly influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are generally accounted for under the equity method. DTE Energy currently owns an 85% interest in SGG, which owns and operates midstream natural gas assets. SGG has contracts through which certain construction risk is designed to pass-through to the customers, with DTE Energy retaining operational and customer default risk. SGG is a VIE with DTE Energy as the primary beneficiary. The Registrants have variable interests in NEXUS, which include DTE Energy's 50% ownership interest and DTE Electric's transportation services contract. NEXUS is a joint venture which owns a 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. NEXUS also owns Generation Pipeline, LLC, a 23-mile regulated pipeline system located in northern Ohio, which was acquired in September 2019. Refer to Note 4 , " Acquisitions ," for additional information. NEXUS is a VIE as it has insufficient equity at risk to finance its activities. The Registrants are not the primary beneficiaries, as the power to direct significant activities is shared between the owners of the equity interests. DTE Energy accounts for its ownership interest in NEXUS under the equity method. The Registrants hold ownership interests in certain limited partnerships. The limited partnerships include investment funds which support regional development and economic growth, as well as, an operational business providing energy-related products. These entities are generally VIEs as a result of certain characteristics of the limited partnership voting rights. The ownership interests are accounted for under the equity method as the Registrants are not the primary beneficiaries. DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of September 30, 2019 , the carrying amount of assets and liabilities in DTE Energy's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase and sale contracts are predominantly related to working capital accounts and generally represent the amounts owed by or to DTE Energy for the deliveries associated with the current billing cycle under the contracts. As of September 30, 2019 , the carrying amount of assets and liabilities in DTE Electric's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominantly related to working capital accounts and generally represent the amounts owed by DTE Electric for the deliveries associated with the current billing cycle under the contracts. The Registrants have not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase contracts. The maximum risk exposure for consolidated VIEs is reflected on the Registrants' Consolidated Statements of Financial Position and, for DTE Energy, in Note 13 to the Consolidated Financial Statements, " Commitments and Contingencies ," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has guaranteed. See Note 13 to the Consolidated Financial Statements, " Commitments and Contingencies ," for further discussion of the NEXUS guarantee arrangements. The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of September 30, 2019 and December 31, 2018 . All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which DTE Energy holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below. Amounts for DTE Energy's consolidated VIEs are as follows: September 30, 2019 December 31, 2018 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 20 $ 12 $ 32 $ 25 $ 14 $ 39 Restricted cash — — — — 5 5 Accounts receivable 10 27 37 9 37 46 Inventories — 97 97 1 92 93 Property, plant, and equipment, net 406 36 442 395 46 441 Goodwill 25 — 25 25 — 25 Intangible assets 546 — 546 557 — 557 Other current and long-term assets 1 — 1 3 — 3 $ 1,008 $ 172 $ 1,180 $ 1,015 $ 194 $ 1,209 LIABILITIES Accounts payable and accrued current liabilities $ 5 $ 18 $ 23 $ 3 $ 31 $ 34 Other current and long-term liabilities 6 7 13 9 10 19 $ 11 $ 25 $ 36 $ 12 $ 41 $ 53 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at September 30, 2019 and 55% at December 31, 2018. Amounts for DTE Energy's non-consolidated VIEs are as follows: September 30, 2019 December 31, 2018 (In millions) Investments in equity method investees $ 1,487 $ 1,425 Notes receivable $ 26 $ 15 Future funding commitments $ 55 $ 55

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Other Income The following is a summary of DTE Energy's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Income from REF entities $ 40 $ 27 $ 96 $ 75 Equity earnings of equity method investees 34 46 77 99 Gains from equity securities 3 5 27 6 Contract services 7 11 21 43 Allowance for equity funds used during construction 5 7 18 20 Other 9 3 20 19 $ 98 $ 99 $ 259 $ 262 The following is a summary of DTE Electric's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Gains from equity securities allocated from DTE Energy $ 3 $ 5 $ 27 $ 6 Contract services 7 11 23 44 Allowance for equity funds used during construction 5 5 17 14 Other 5 2 11 8 $ 20 $ 23 $ 78 $ 72 Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is the change in common shareholders' equity during a period from transactions and events from non-owner sources, including Net Income. The amounts recorded to Accumulated other comprehensive income (loss) for DTE Energy include changes in benefit obligations, consisting of deferred actuarial losses and prior service costs, unrealized gains and losses from derivatives accounted for as cash flow hedges, DTE Energy's interest in other comprehensive income of equity investees which comprise the net unrealized gains and losses on investments, and foreign currency translation adjustments. DTE Energy releases income tax effects from accumulated other comprehensive income when the circumstances upon which they are premised cease to exist. Changes in Accumulated other comprehensive income (loss) are presented in DTE Energy's Consolidated Statements of Changes in Equity and DTE Electric's Consolidated Statements of Changes in Shareholder's Equity. For further discussion regarding changes in Accumulated other comprehensive income (loss), see Note 3 to the Consolidated Financial Statements, " New Accounting Pronouncements ." For the three and nine months ended September 30, 2019 and 2018 , reclassifications out of Accumulated other comprehensive income (loss) not relating to the adoption of new accounting pronouncements for DTE Energy were not material. Income Taxes The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 DTE Energy 13 % 9 % 12 % 12 % DTE Electric 16 % 21 % 16 % 22 % These tax rates are affected by estimated annual permanent items, including AFUDC equity, production tax credits, and other flow-through items, as well as discrete items that may occur in any given period, but are not consistent from period to period. The 4% increase in DTE Energy's effective tax rate for the three months ended September 30, 2019 was primarily due to a decrease in annual production tax credits, partially offset by the amortization of the TCJA regulatory liability in 2019 and the $20 million valuation allowance for the AMT credit carryover in 2018. There was no change in DTE Energy's effective tax rate for the nine months ended September 30, 2019 . This was primarily due to a decrease in annual production tax credits, offset by the amortization of the TCJA regulatory liability in 2019, true-up adjustments to the remeasurement of deferred taxes in 2018 of $21 million , and the $20 million valuation allowance for the AMT credit carryover in 2018. The 5% and 6% decrease in DTE Electric's effective tax rate for the three and nine months ended September 30, 2019 , respectively, was primarily due to the amortization of the TCJA regulatory liability of 4% and higher production tax credits of 1% in 2019. The additional 1% decrease for the nine months ended September 30, 2019 was due to the remeasurement of deferred taxes in 2018 of $7 million . DTE Energy's total amount of unrecognized tax benefits as of September 30, 2019 was $8 million , which if recognized, would favorably impact its effective tax rate. DTE Electric's total amount of unrecognized tax benefits as of September 30, 2019 was $10 million , which if recognized, would favorably impact its effective tax rate. The Registrants do not anticipate any material changes to the unrecognized tax benefits in the next twelve months. DTE Electric had income tax payables of $13 million with DTE Energy at September 30, 2019 and income tax receivables with DTE Energy of $8 million at December 31, 2018 . Unrecognized Compensation Costs As of September 30, 2019 , DTE Energy had $88 million of total unrecognized compensation cost related to non-vested stock incentive plan arrangements. That cost is expected to be recognized over a weighted-average period of 1.30 years . Allocated Stock-Based Compensation DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation of $9 million and $11 million for the three months ended September 30, 2019 and 2018, respectively , while such allocation was $33 million and $27 million for the nine months ended September 30, 2019 and 2018, respectively . Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held to satisfy requirements of certain debt and DTE Energy partnership operating agreements. Restricted cash designated for interest and principal payments within one year is classified as a Current Asset. Intangible Assets The Registrants have certain Intangible assets as shown below: September 30, 2019 December 31, 2018 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 779 $ (58 ) $ 721 $ 779 $ (44 ) $ 735 Contract intangibles 6 to 26 years 270 (72 ) 198 159 (66 ) 93 1,049 (130 ) 919 938 (110 ) 828 DTE Electric renewable energy credits (b) 20 — 20 20 — 20 DTE Electric emission allowances (b) 1 — 1 1 — 1 21 — 21 21 — 21 Long-term intangible assets DTE Electric $ 21 $ — $ 21 $ 21 $ — $ 21 DTE Energy $ 1,070 $ (130 ) $ 940 $ 959 $ (110 ) $ 849 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business. The following table summarizes DTE Energy's estimated customer relationship and contract intangible amortization expense expected to be recognized during each year through 2024: Remaining 2019 2020 2021 2022 2023 2024 (In millions) Estimated amortization expense $ 9 $ 35 $ 34 $ 34 $ 34 $ 34 DTE Energy amortizes customer relationship and contract intangible assets on a straight-line basis over the expected period of benefit. DTE Energy's Intangible assets amortization expense was $7 million for the three months ended September 30, 2019 and 2018 , while amortization expense was $21 million and $20 million for the nine months ended September 30, 2019 and 2018 , respectively.

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS Recently Adopted Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), as amended. This guidance requires a lessee to account for leases as finance or operating leases and disclose key information about leasing arrangements. Both types of leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition, depending on the lease classification. The Registrants adopted the standard on January 1, 2019 using the prospective approach. The standard provides a number of transition practical expedients of which the Registrants elected the package of three expedients that must be taken together, allowing entities to not reassess whether an agreement is a lease, to carryforward the existing lease classification, and to not reassess initial direct costs associated with existing leases; but did not elect to apply hindsight in determining lease term and impairment of the right-of-use assets. The Registrants also elected to not evaluate land easements under the new guidance at adoption if they were not previously accounted for as leases. These practical expedients apply to leases that commenced prior to January 1, 2019. At adoption of the new standard, the Registrants recognized on the Consolidated Statements of Financial Position, right-of-use assets and lease liabilities for certain operating leases of approximately $137 million and $130 million , respectively, for DTE Energy and approximately $74 million and $67 million , respectively, for DTE Electric as of January 1, 2019. The right-of-use lease assets include $9 million of prepaid lease costs that have been reclassified from Other assets, current and noncurrent, and $2 million of deferred lease costs that have been reclassified from Other liabilities, current and noncurrent, for the Registrants. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Statements of Operations but required additional disclosures for leases. See Note 12 to the Consolidated Financial Statements, " Leases ." In February 2018, the FASB issued ASU No. 2018-02, Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings from stranded tax effects resulting from the TCJA. The amendments in this update also require entities to disclose their accounting policy for releasing income tax effects from accumulated other comprehensive income. The Registrants adopted the standard effective January 1, 2019. Upon adoption, DTE Energy reclassified $25 million of income tax effects from Accumulated other comprehensive income (loss) to Retained Earnings. Recently Issued Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as amended. The amendments in this update replace the incurred loss impairment methodology in current generally accepted accounting principles with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasts, to develop credit loss estimates. The ASU requires entities to use the new methodology to measure impairment of financial instruments, including accounts receivable, and may result in earlier recognition of credit losses than under current generally accepted accounting principles. Entities will apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The ASU is effective for the Registrants beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement . The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-14, Compensation — Retirement Benefits — Defined Benefit Plans (Subtopic 715-20): Disclosure Framework — Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans . The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The ASU is effective for the Registrants for fiscal years ending after December 15, 2020. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract . The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The ASU may be applied using either a retrospective or prospective approach. The Registrants are currently evaluating the transition methods and assessing the impact of this standard on their Consolidated Financial Statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities . The amendments in this update modify the requirements for determining whether a decision-making fee is a variable interest and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Electric Segment Acquisition Effective September 12, 2019, DTE Energy closed on the purchase of an 89 MW renewable energy project located in Michigan from Heritage Sustainable Energy in support of renewable energy goals. Direct transaction costs primarily related to advisory fees were immaterial and are included in Operation and maintenance in DTE Energy's Consolidated Statements of Operations. The consideration paid for the entity acquired was approximately $174 million in cash. The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 111 Property, plant, and equipment, net 59 Working capital 4 Total $ 174 The intangible assets recorded pertain to existing customer contracts and were estimated by applying the income approach, based on discounted projected cash flows attributable to the existing agreements. The contract intangible assets are amortized on a straight line basis with useful lives ranging from 11 years to 14 years , which is based on the remaining number of years the assets are expected to economically contribute to the business. The pro forma financial information has not been presented for DTE Energy because the effects of the acquisition were not material to the Consolidated Statements of Operations. Concurrent with the above acquisition, DTE Energy entered into a separate purchase and sale agreement with Heritage Sustainable Energy to acquire an additional renewable energy project for approximately $30 million . This transaction is expected to close in early January 2020. Gas Storage and Pipelines Segment Acquisition Effective September 20, 2019, NEXUS closed on the purchase of Generation Pipeline, LLC, a pipeline system regulated by the Public Utilities Commission of Ohio. The 23-mile pipeline system supplies gas to industrial customers in the Toledo, OH area, has existing interconnects with ANR Pipeline Company and Panhandle Eastern Pipeline Company, and is located four miles from NEXUS. Total consideration paid for the acquired entity was approximately $163 million , of which DTE Energy's portion was 50% . DTE Energy accounts for its ownership interest in NEXUS under the equity method, which will now include equity in earnings related to Generation Pipeline, LLC.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Disaggregation of Revenue The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Electric (a) Residential $ 791 $ 773 $ 1,839 $ 1,943 Commercial 515 495 1,358 1,370 Industrial 175 173 497 527 Other (b) 39 80 251 162 Total Electric operating revenues (c) $ 1,520 $ 1,521 $ 3,945 $ 4,002 Gas Gas sales $ 87 $ 89 $ 727 $ 726 End User Transportation 35 34 157 168 Intermediate Transportation 15 9 57 38 Other (b) 18 32 102 37 Total Gas operating revenues (d) $ 155 $ 164 $ 1,043 $ 969 Other segment operating revenues Gas Storage and Pipelines (e) $ 126 $ 122 $ 363 $ 363 Power and Industrial Projects (f) $ 406 $ 612 $ 1,196 $ 1,717 Energy Trading (g) $ 1,105 $ 1,332 $ 3,519 $ 3,994 _______________________________________ (a) Revenues under the Electric segment generally represent those of DTE Electric. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $5 million and $6 million of other revenues outside the scope of Topic 606 for the three months ended September 30, 2019 and 2018, respectively , and $14 million and $15 million for the nine months ended September 30, 2019 and 2018 , respectively. (d) Includes $4 million under Alternative Revenue Programs for the nine months ended September 30, 2018 . Also includes $2 million of other revenues for the three months ended September 30, 2019 and 2018 and $6 million for the nine months ended September 30, 2019 and 2018 , which are both outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million and $7 million of contracts accounted for as leases for the three and nine months ended September 30, 2019 , respectively. (f) Includes revenues outside the scope of Topic 606 primarily related to $33 million and $37 million of contracts accounted for as leases for the three months ended September 30, 2019 and 2018, respectively , and $94 million and $93 million for the nine months ended September 30, 2019 and 2018 , respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $791 million and $1.1 billion of derivatives for the three months ended September 30, 2019 and 2018, respectively , and $2.6 billion and $3.2 billion of derivatives for the nine months ended September 30, 2019 and 2018 , respectively. Deferred Revenue The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2019 $ 74 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 41 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (50 ) Ending Balance, September 30, 2019 $ 65 The deferred revenues at DTE Energy generally represent amounts paid by or receivable from customers for which the associated performance obligation has not yet been satisfied. Deferred revenues include amounts associated with REC performance obligations under certain wholesale full requirements power contracts. Deferred revenues associated with RECs are recognized as revenue when control of the RECs has transferred. Other performance obligations associated with deferred revenues include providing products and services related to customer prepayments. Deferred revenues associated with these products and services are recognized when control has transferred to the customer. The following table represents deferred revenue amounts for DTE Energy that are expected to be recognized as revenue in future periods: DTE Energy (In millions) 2019 $ 9 2020 25 2021 6 2022 7 2023 6 2024 and thereafter 12 $ 65 Transaction Price Allocated to the Remaining Performance Obligations In accordance with optional exemptions available under Topic 606, the Registrants did not disclose the value of unsatisfied performance obligations for (1) contracts with an original expected length of one year or less, (2) with the exception of fixed consideration, contracts for which revenue is recognized at the amount to which the Registrants have the right to invoice for goods provided and services performed, and (3) contracts for which variable consideration relates entirely to an unsatisfied performance obligation. Such contracts consist of varying types of performance obligations across the segments, including the supply and delivery of energy related products and services. Contracts with variable volumes and/or variable pricing, including those with pricing provisions tied to a consumer price or other index, have also been excluded as the related consideration under the contract is variable at inception of the contract. Contract lengths vary from cancelable to multi-year. The Registrants expect to recognize revenue for the following amounts related to fixed consideration associated with remaining performance obligations in each of the future periods noted: DTE Energy DTE Electric (In millions) 2019 $ 52 $ 3 2020 290 — 2021 269 — 2022 206 — 2023 142 — 2024 and thereafter 648 — $ 1,607 $ 3 Other Matters The following table represents expenses recognized for estimated uncollectible accounts receivable: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) DTE Energy $ 28 $ 39 $ 81 $ 95 DTE Electric $ 17 $ 26 $ 47 $ 57

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2019
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	REGULATORY MATTERS 2018 Electric Rate Case Filing DTE Electric filed a rate case with the MPSC on July 6, 2018 requesting an increase in base rates of $328 million based on a projected twelve-month period ending April 30, 2020. The requested increase in base rates was primarily due to an increase in net plant resulting from infrastructure investments, depreciation expense, as requested in the 2016 DTE Electric Depreciation Case Filing, and reliability improvement projects. The rate filing also requested an increase in return on equity from 10.0% to 10.5% and included projected changes in sales, operation and maintenance expenses, and working capital. In addition, the rate filing requested an Infrastructure Recovery Mechanism to recover the incremental revenue requirement associated with certain distribution, fossil generation, and nuclear generation capital expenditures through 2022. Finally, as noted in the 2017 Tax Reform section below, DTE Electric proposed an amortization schedule for Calculation C in this filing. On February 1, 2019, DTE Electric reduced its initial requested increase in base rates to $248.6 million , primarily reflecting the reduction in requested depreciation expense resulting from the MPSC's approval of new depreciation rates. On May 2, 2019, the MPSC issued an order approving an annual revenue increase of $125 million for services rendered on or after May 9, 2019. The MPSC authorized a return on equity of 10.0% . In addition, the order approved the proposed amortization schedule for Calculation C but denied the requested Infrastructure Recovery Mechanism. 2019 Electric Rate Case Filing DTE Electric filed a rate case with the MPSC on July 8, 2019 requesting an increase in base rates of $351 million based on a projected twelve-month period ending April 30, 2021. The requested increase in base rates is primarily due to an increase in net plant resulting from infrastructure and generation investments. The rate filing also requests an increase in return on equity from 10.0% to 10.5% and includes projected changes in sales and operating and maintenance expenses. A final MPSC order in this case is expected by May 2020. 2016 DTE Electric Depreciation Case Filing DTE Electric filed a depreciation case with the MPSC on November 1, 2016 requesting an increase in depreciation rates for plant in service balances as of December 31, 2015. The MPSC issued an order on December 6, 2018 authorizing DTE Electric to increase its composite depreciation rate from 3.06% to 3.72% . The new rates are effective for service rendered on or after May 9, 2019, per the final order in DTE Electric's 2018 rate case issued on May 2, 2019. 2017 Tax Reform On December 27, 2017, the MPSC issued an order to consider changes in the rates of all Michigan rate-regulated utilities to reflect the effects of the federal TCJA. On January 19, 2018, DTE Electric and DTE Gas filed information with the MPSC regarding the potential change in revenue requirements due to the TCJA effective January 1, 2018 and outlined their recommended method to flow the current and deferred tax benefits of those impacts to ratepayers. On February 22, 2018, the MPSC issued an order in this case requiring utilities, including DTE Electric and DTE Gas, to follow a 3-step approach of credits and calculations. In 2018, MPSC orders for the first two steps, Credit A and Credit B, were issued for DTE Electric and DTE Gas. The third step is to perform Calculation C to address all remaining issues relative to the new tax law, which is primarily the remeasurement of deferred taxes and how the amounts deferred as Regulatory liabilities will flow to ratepayers. DTE Gas filed its Calculation C case on November 16, 2018 to reduce the annual revenue requirement by $12 million related to the amortization of deferred tax remeasurement. On August 20, 2019, the MPSC issued an order in this case approving a $13 million reduction to DTE Gas' annual revenue requirement. This reduction in revenue will be offset by a corresponding reduction in income tax expense within the Consolidated Statements of Operations. DTE Electric proposed an amortization schedule for Calculation C in its general rate case filed July 6, 2018, which was approved by the MPSC in the May 2, 2019 rate order.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is calculated by dividing the net income, adjusted for income allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted earnings per share reflect the dilution that would occur if any potentially dilutive instruments were exercised or converted into common shares. DTE Energy’s participating securities are restricted shares under the stock incentive program that contain rights to receive non-forfeitable dividends. Equity units, performance shares, and stock options do not receive cash dividends; as such, these awards are not considered participating securities. The following is a reconciliation of DTE Energy's basic and diluted income per share calculation: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — basic $ 318 $ 333 $ 900 $ 927 Average number of common shares outstanding — basic 183 182 183 181 Basic Earnings per Common Share $ 1.74 $ 1.84 $ 4.93 $ 5.13 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — diluted $ 318 $ 333 $ 900 $ 927 Average number of common shares outstanding — basic 183 182 183 181 Incremental shares attributable to: Average dilutive equity units, performance share awards, and stock options 1 — 1 — Average number of common shares outstanding — diluted 184 182 184 181 Diluted Earnings per Common Share (a) $ 1.73 $ 1.84 $ 4.91 $ 5.13 _______________________________________ (a) The 2016 Equity Units excluded from the calculation of diluted EPS were approximately 6.2 million for the three months ended September 30, 2018 and 6.4 million for the nine months ended September 30, 2018 as the dilutive stock price threshold was not met. On October 1, 2019, DTE Energy issued approximately 5.87 million shares of common stock under the stock purchase contracts associated with DTE Energy's 2016 Series C Equity Units for $675 million . Refer to Note 10 to the Consolidated Financial Statements, " Long-Term Debt " for additional information.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. The Registrants make certain assumptions they believe that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at September 30, 2019 and December 31, 2018 . The Registrants believe they use valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Registrants classify fair value balances based on the fair value hierarchy defined as follows: • Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Registrants have the ability to access as of the reporting date. • Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints. The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis (a) : September 30, 2019 December 31, 2018 Level Level Level Other (b) Netting (c) Net Balance Level Level Level Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 21 $ — $ — $ — $ — $ 21 $ 16 $ 2 $ — $ — $ — $ 18 Nuclear decommissioning trusts Equity securities 990 — — — — 990 851 — — — — 851 Fixed income securities 9 535 — — — 544 12 490 — — — 502 Private equity and other — — — 34 — 34 — — — 20 — 20 Cash equivalents 9 — — — — 9 5 — — — — 5 Other investments (e) Equity securities 130 — — — — 130 110 — — — — 110 Fixed income securities 78 — — — — 78 69 — — — — 69 Cash equivalents 4 — — — — 4 4 — — — — 4 Derivative assets Commodity contracts Natural gas 109 90 54 — (189 ) 64 199 87 63 — (277 ) 72 Electricity — 128 36 — (124 ) 40 — 247 56 — (252 ) 51 Other 5 — 5 — (5 ) 5 — — 7 — (1 ) 6 Foreign currency exchange contracts — 2 — — — 2 — 4 — — — 4 Total derivative assets 114 220 95 — (318 ) 111 199 338 126 — (530 ) 133 Total $ 1,355 $ 755 $ 95 $ 34 $ (318 ) $ 1,921 $ 1,266 $ 830 $ 126 $ 20 $ (530 ) $ 1,712 Liabilities Derivative liabilities Commodity contracts Natural gas $ (130 ) $ (72 ) $ (95 ) $ — $ 189 $ (108 ) $ (197 ) $ (71 ) $ (112 ) $ — $ 272 $ (108 ) Electricity — (127 ) (28 ) — 124 (31 ) — (227 ) (58 ) — 240 (45 ) Other (7 ) (1 ) — — 5 (3 ) — (1 ) — — 1 — Interest rate contracts — — — — — — — (3 ) — — — (3 ) Total derivative liabilities (137 ) (200 ) (123 ) — 318 (142 ) (197 ) (302 ) (170 ) — 513 (156 ) Total $ (137 ) $ (200 ) $ (123 ) $ — $ 318 $ (142 ) $ (197 ) $ (302 ) $ (170 ) $ — $ 513 $ (156 ) Net Assets (Liabilities) at end of period $ 1,218 $ 555 $ (28 ) $ 34 $ — $ 1,779 $ 1,069 $ 528 $ (44 ) $ 20 $ (17 ) $ 1,556 Assets Current $ 130 $ 175 $ 62 $ — $ (271 ) $ 96 $ 212 $ 273 $ 96 $ — $ (461 ) $ 120 Noncurrent 1,225 580 33 34 (47 ) 1,825 1,054 557 30 20 (69 ) 1,592 Total Assets $ 1,355 $ 755 $ 95 $ 34 $ (318 ) $ 1,921 $ 1,266 $ 830 $ 126 $ 20 $ (530 ) $ 1,712 Liabilities Current $ (123 ) $ (163 ) $ (53 ) $ — $ 271 $ (68 ) $ (191 ) $ (251 ) $ (76 ) $ — $ 451 $ (67 ) Noncurrent (14 ) (37 ) (70 ) — 47 (74 ) (6 ) (51 ) (94 ) — 62 (89 ) Total Liabilities $ (137 ) $ (200 ) $ (123 ) $ — $ 318 $ (142 ) $ (197 ) $ (302 ) $ (170 ) $ — $ 513 $ (156 ) Net Assets (Liabilities) at end of period $ 1,218 $ 555 $ (28 ) $ 34 $ — $ 1,779 $ 1,069 $ 528 $ (44 ) $ 20 $ (17 ) $ 1,556 _______________________________________ (a) See footnotes on following page. _______________________________________ (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties. (d) At September 30, 2019 , the $21 million consisted of $10 million and $11 million of cash equivalents included in Cash and cash equivalents and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2018 , the $18 million consisted of $3 million , $5 million and $10 million of cash equivalents included in Cash and cash equivalents, Restricted cash, and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. (e) Excludes cash surrender value of life insurance investments. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of: September 30, 2019 December 31, 2018 Level 1 Level 2 Level 3 Other (a) Net Balance Level 1 Level 2 Level 3 Other (a) Net Balance (In millions) Assets Cash equivalents (b) $ 11 $ — $ — $ — $ 11 $ 8 $ 2 $ — $ — $ 10 Nuclear decommissioning trusts Equity securities 990 — — — 990 851 — — — 851 Fixed income securities 9 535 — — 544 12 490 — — 502 Private equity and other — — — 34 34 — — — 20 20 Cash equivalents 9 — — — 9 5 — — — 5 Other investments Equity securities 12 — — — 12 10 — — — 10 Derivative assets — FTRs — — 5 — 5 — — 6 — 6 Total $ 1,031 $ 535 $ 5 $ 34 $ 1,605 $ 886 $ 492 $ 6 $ 20 $ 1,404 Assets Current $ 11 $ — $ 5 $ — $ 16 $ 8 $ 2 $ 6 $ — $ 16 Noncurrent 1,020 535 — 34 1,589 878 490 — 20 1,388 Total Assets $ 1,031 $ 535 $ 5 $ 34 $ 1,605 $ 886 $ 492 $ 6 $ 20 $ 1,404 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At September 30, 2019 , the $11 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2018 , the $10 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. Cash Equivalents Cash equivalents include investments with maturities of three months or less when purchased. The cash equivalents shown in the fair value table are comprised of short-term investments and money market funds. Nuclear Decommissioning Trusts and Other Investments The nuclear decommissioning trusts and other investments hold debt and equity securities directly and indirectly through commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. Commingled funds that hold exchange-traded equity or debt securities are valued based on stated NAVs. Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. Other assets such as private equity investments are classified as NAV assets. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered preferable. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Derivative Assets and Liabilities Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options, and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. The Registrants consider the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time, and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality, and basis differential factors. The Registrants monitor the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Registrants have established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy. The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of June 30 $ (10 ) $ 10 $ 9 $ 9 $ (25 ) $ (13 ) $ 15 $ (23 ) Transfers into Level 3 from Level 2 — — — — — — — — Transfers from Level 3 into Level 2 — — — — — — — — Total gains (losses) Included in earnings (35 ) 37 — 2 (30 ) 21 — (9 ) Recorded in Regulatory liabilities — — (3 ) (3 ) — — (8 ) (8 ) Purchases, issuances, and settlements Settlements 4 (39 ) (1 ) (36 ) 9 (18 ) (1 ) (10 ) Net Assets (Liabilities) as of September 30 $ (41 ) $ 8 $ 5 $ (28 ) $ (46 ) $ (10 ) $ 6 $ (50 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (36 ) $ 15 $ (1 ) $ (22 ) $ (31 ) $ 10 $ (1 ) $ (22 ) Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (49 ) $ (2 ) $ 7 $ (44 ) $ (29 ) $ 12 $ 8 $ (9 ) Transfers into Level 3 from Level 2 — — — — — — — — Transfers from Level 3 into Level 2 — — — — (3 ) — — (3 ) Total gains (losses) Included in earnings (4 ) 47 (1 ) 42 (128 ) 25 1 (102 ) Recorded in Regulatory liabilities — — 3 3 — — 6 6 Purchases, issuances, and settlements Settlements 12 (37 ) (4 ) (29 ) 114 (47 ) (9 ) 58 Net Assets (Liabilities) as of September 30 $ (41 ) $ 8 $ 5 $ (28 ) $ (46 ) $ (10 ) $ 6 $ (50 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (20 ) $ 32 $ (6 ) $ 6 $ (109 ) $ 4 $ (3 ) $ (108 ) The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Net Assets as of beginning of period $ 9 $ 15 $ 6 $ 9 Change in fair value recorded in Regulatory liabilities (3 ) (8 ) 3 6 Purchases, issuances, and settlements Settlements (1 ) (1 ) (4 ) (9 ) Net Assets as of September 30 $ 5 $ 6 $ 5 $ 6 The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2019 and 2018 and reflected in DTE Electric's Consolidated Statements of Financial Position $ (1 ) $ (2 ) $ 5 $ 6 Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period. There were no transfers between Levels 1 and 2 for the Registrants during the three and nine months ended September 30, 2019 and 2018 , and there were no transfers from or into Level 3 for DTE Electric during the same periods. The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities: September 30, 2019 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 54 $ (95 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.55 ) — $ 6.17 /MMBtu $ (0.09 )/MMBtu Electricity $ 36 $ (28 ) Discounted Cash Flow Forward basis price (per MWh) $ (13 ) — $ 7 /MWh $ — December 31, 2018 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 63 $ (112 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (2.15 ) — $ 5.59 /MMBtu $ (0.10 )/MMBtu Electricity $ 56 $ (58 ) Discounted Cash Flow Forward basis price (per MWh) $ (7 ) — $ 9 /MWh $ 1 /MWh The unobservable inputs used in the fair value measurement of the electricity and natural gas commodity types consist of inputs that are less observable due in part to lack of available broker quotes, supported by little, if any, market activity at the measurement date or are based on internally developed models. Certain basis prices (i.e., the difference in pricing between two locations) included in the valuation of natural gas and electricity contracts were deemed unobservable. The inputs listed above would have a direct impact on the fair values of the above security types if they were adjusted. A significant increase (decrease) in the basis price would result in a higher (lower) fair value for long positions, with offsetting impacts to short positions. Fair Value of Financial Instruments The following table presents the carrying amount and fair value of financial instruments for DTE Energy: September 30, 2019 December 31, 2018 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) , excluding lessor finance leases $ 178 $ — $ — $ 178 $ 40 $ — $ — $ 40 Dividends payable $ 173 $ 173 $ — $ — $ 172 $ 172 $ — $ — Short-term borrowings $ 724 $ — $ 724 $ — $ 609 $ — $ 609 $ — Notes payable — Other (b) , excluding lessee finance leases $ 27 $ — $ — $ 27 $ 41 $ — $ — $ 41 Long-term debt (c) $ 15,056 $ 1,277 $ 14,216 $ 1,138 $ 13,622 $ 1,796 $ 10,712 $ 1,317 _______________________________________ (a) Current portion included in Current Assets — Other on DTE Energy's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Energy's Consolidated Statements of Financial Position. (c) Includes debt due within one year , unamortized debt discounts, and issuance costs. Excludes finance lease obligations. The following table presents the carrying amount and fair value of financial instruments for DTE Electric: September 30, 2019 December 31, 2018 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable — Other (a) , excluding lessor finance leases $ 14 $ — $ — $ 14 $ 6 $ — $ — $ 6 Short-term borrowings — affiliates $ 97 $ — $ — $ 97 $ 101 $ — $ — $ 101 Short-term borrowings — other $ 382 $ — $ 382 $ — $ 149 $ — $ 149 $ — Notes payable — Other (b) , excluding lessee finance leases $ 23 $ — $ — $ 23 $ 21 $ — $ — $ 21 Long-term debt (c) $ 7,179 $ — $ 7,996 $ 176 $ 6,538 $ — $ 6,552 $ 161 _______________________________________ (a) Included in Current Assets — Other on DTE Electric's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Electric's Consolidated Statements of Financial Position. (c) Includes debt due within one year , unamortized debt discounts, and issuance costs. Excludes finance lease obligations. For further fair value information on financial and derivative instruments, see Note 9 to the Consolidated Financial Statements, " Financial and Other Derivative Instruments ." Nuclear Decommissioning Trust Funds DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of its operating licenses. This obligation is reflected as an Asset retirement obligation on DTE Electric's Consolidated Statements of Financial Position. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: September 30, 2019 December 31, 2018 (In millions) Fermi 2 $ 1,567 $ 1,372 Fermi 1 3 3 Low-level radioactive waste 7 3 $ 1,577 $ 1,378 The costs of securities sold are determined on the basis of specific identification. The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Realized gains $ 15 $ 10 $ 43 $ 52 Realized losses $ (8 ) $ (7 ) $ (25 ) $ (22 ) Proceeds from sale of securities $ 198 $ 194 $ 594 $ 810 Realized gains and losses from the sale of securities and unrealized gains and losses incurred by the Fermi 2 trust are recorded to the Regulatory asset and Nuclear decommissioning liability. Realized gains and losses from the sale of securities and unrealized gains and losses on the low-level radioactive waste funds are recorded to the Nuclear decommissioning liability. The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds: September 30, 2019 December 31, 2018 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 990 $ 335 $ (53 ) $ 851 $ 235 $ (79 ) Fixed income securities 544 27 (1 ) 502 7 (8 ) Private equity and other 34 — — 20 — — Cash equivalents 9 — — 5 — — $ 1,577 $ 362 $ (54 ) $ 1,378 $ 242 $ (87 ) The following table summarizes the fair value of the fixed income securities held in nuclear decommissioning trust funds by contractual maturity: September 30, 2019 (In millions) Due within one year $ 23 Due after one through five years 98 Due after five through ten years 108 Due after ten years 315 $ 544 Other Securities At September 30, 2019 and December 31, 2018 , the Registrants' securities, included in Other investments on the Consolidated Statements of Financial Position, were comprised primarily of money market and equity securities. For the three months ended September 30, 2019 and 2018 , gains related to equity securities were $3 million and $5 million , respectively. For the nine months ended September 30, 2019 and 2018 , gains related to equity securities were $27 million and $4 million , respectively. Gains or losses related to the Rabbi Trust assets are allocated from DTE Energy to DTE Electric.

Financial and Other Derivative

Financial and Other Derivative Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period. The Registrants' primary market risk exposure is associated with commodity prices, credit, and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil, certain coal forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized. DTE Gas — DTE Gas purchases, stores, transports, distributes, and sells natural gas and sells storage and transportation capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2022. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. DTE Gas may also sell forward transportation and storage capacity contracts. Forward transportation and storage contracts are generally not derivatives and are therefore accounted for under the accrual method. Gas Storage and Pipelines — This segment is primarily engaged in services related to the gathering, transportation, and storage of natural gas. Primarily fixed-priced contracts are used in the marketing and management of transportation and storage services. Generally, these contracts are not derivatives and are therefore accounted for under the accrual method. Power and Industrial Projects — This segment manages and operates energy and pulverized coal projects, a coke battery, reduced emissions fuel projects, renewable gas recovery, and power generation assets. Primarily fixed-price contracts are used in the marketing and management of the segment assets. These contracts are generally not derivatives and are therefore accounted for under the accrual method. Energy Trading — Commodity Price Risk — Energy Trading markets and trades electricity, natural gas physical products, and energy financial instruments, and provides energy and asset management services utilizing energy commodity derivative instruments. Forwards, futures, options, and swap agreements are used to manage exposure to the risk of market price and volume fluctuations in its operations. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Energy Trading — Foreign Currency Exchange Risk — Energy Trading has foreign currency exchange forward contracts to economically hedge fixed Canadian dollar commitments existing under natural gas and power purchase and sale contracts and natural gas transportation contracts. Energy Trading enters into these contracts to mitigate price volatility with respect to fluctuations of the Canadian dollar relative to the U.S. dollar. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Corporate and Other — Interest Rate Risk — DTE Energy may use interest rate swaps, treasury locks, and other derivatives to hedge the risk associated with interest rate market volatility. Credit Risk — DTE Energy maintains credit policies that significantly minimize overall credit risk. These policies include an evaluation of potential customers’ and counterparties’ financial condition, including the viability of underlying productive assets, credit rating, collateral requirements, or other credit enhancements such as letters of credit or guarantees. DTE Energy generally uses standardized agreements that allow the netting of positive and negative transactions associated with a single counterparty. DTE Energy maintains a provision for credit losses based on factors surrounding the credit risk of its customers, historical trends, and other information. Based on DTE Energy's credit policies and its September 30, 2019 provision for credit losses, DTE Energy’s exposure to counterparty nonperformance is not expected to have a material adverse effect on DTE Energy's Consolidated Financial Statements. Derivative Activities DTE Energy manages its MTM risk on a portfolio basis based upon the delivery period of its contracts and the individual components of the risks within each contract. Accordingly, it records and manages the energy purchase and sale obligations under its contracts in separate components based on the commodity (e.g. electricity or natural gas), the product (e.g. electricity for delivery during peak or off-peak hours), the delivery location (e.g. by region), the risk profile (e.g. forward or option), and the delivery period (e.g. by month and year). The following describes the categories of activities represented by their operating characteristics and key risks: • Asset Optimization — Represents derivative activity associated with assets owned and contracted by DTE Energy, including forward natural gas purchases and sales, natural gas transportation, and storage capacity. Changes in the value of derivatives in this category typically economically offset changes in the value of underlying non-derivative positions, which do not qualify for fair value accounting. The difference in accounting treatment of derivatives in this category and the underlying non-derivative positions can result in significant earnings volatility. • Marketing and Origination — Represents derivative activity transacted by originating substantially hedged positions with wholesale energy marketers, producers, end-users, utilities, retail aggregators, and alternative energy suppliers. • Fundamentals Based Trading — Represents derivative activity transacted with the intent of taking a view, capturing market price changes, or putting capital at risk. This activity is speculative in nature as opposed to hedging an existing exposure. • Other — Includes derivative activity at DTE Electric related to FTRs. Changes in the value of derivative contracts at DTE Electric are recorded as Derivative assets or liabilities, with an offset to Regulatory assets or liabilities as the settlement value of these contracts will be included in the PSCR mechanism when realized. The following table presents the fair value of derivative instruments for DTE Energy: September 30, 2019 December 31, 2018 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Interest rate contracts $ — $ — $ — $ (3 ) Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 253 $ (297 ) $ 349 $ (380 ) Electricity 164 (155 ) 303 (285 ) Other 10 (8 ) 7 (1 ) Foreign currency exchange contracts 2 — 4 — Total derivatives not designated as hedging instruments $ 429 $ (460 ) $ 663 $ (666 ) Current $ 346 $ (339 ) $ 563 $ (518 ) Noncurrent 83 (121 ) 100 (151 ) Total derivatives $ 429 $ (460 ) $ 663 $ (669 ) The following table presents the fair value of derivative instruments for DTE Electric: September 30, 2019 December 31, 2018 (In millions) FTRs — Other current assets $ 5 $ 6 Total derivatives not designated as hedging instruments $ 5 $ 6 Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of $2 million and $4 million outstanding at September 30, 2019 and December 31, 2018 , respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $6 million and $8 million at September 30, 2019 and December 31, 2018 , respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. For contracts with certain clearing agents, the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a Derivative asset or liability or 2) an Account receivable or payable. Other than certain clearing agents, Accounts receivable and Accounts payable that are subject to netting arrangements have not been offset against the fair value of Derivative assets and liabilities. The following table presents net cash collateral offsetting arrangements for DTE Energy: September 30, 2019 December 31, 2018 (In millions) Cash collateral netted against Derivative assets $ — $ (17 ) Cash collateral recorded in Accounts receivable (a) 9 10 Cash collateral recorded in Accounts payable (a) (6 ) (6 ) Total net cash collateral posted (received) $ 3 $ (13 ) _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 2019 December 31, 2018 Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position (In millions) Derivative assets Commodity contracts Natural gas $ 253 $ (189 ) $ 64 $ 349 $ (277 ) $ 72 Electricity 164 (124 ) 40 303 (252 ) 51 Other 10 (5 ) 5 7 (1 ) 6 Foreign currency exchange contracts 2 — 2 4 — 4 Total derivative assets $ 429 $ (318 ) $ 111 $ 663 $ (530 ) $ 133 Derivative liabilities Commodity contracts Natural gas $ (297 ) $ 189 $ (108 ) $ (380 ) $ 272 $ (108 ) Electricity (155 ) 124 (31 ) (285 ) 240 (45 ) Other (8 ) 5 (3 ) (1 ) 1 — Interest rate contracts — — — (3 ) — (3 ) Total derivative liabilities $ (460 ) $ 318 $ (142 ) $ (669 ) $ 513 $ (156 ) The following table presents the netting offsets of Derivative assets and liabilities showing the reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position: September 30, 2019 December 31, 2018 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 346 $ 83 $ (339 ) $ (121 ) $ 563 $ 100 $ (518 ) $ (151 ) Counterparty netting (271 ) (47 ) 271 47 (451 ) (62 ) 451 62 Collateral adjustment — — — — (10 ) (7 ) — — Total derivatives as reported $ 75 $ 36 $ (68 ) $ (74 ) $ 102 $ 31 $ (67 ) $ (89 ) The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations is as follows: Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended September 30, Gain (Loss) Recognized in Income on Derivatives for the Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (5 ) $ (29 ) $ 4 $ (51 ) Natural gas Fuel, purchased power, and gas — non-utility (47 ) (6 ) (7 ) (74 ) Electricity Operating Revenues — Non-utility operations 54 26 21 37 Other Operating Revenues — Non-utility operations (11 ) — (11 ) 1 Foreign currency exchange contracts Operating Revenues — Non-utility operations 1 (2 ) (2 ) 2 Total $ (8 ) $ (11 ) $ 5 $ (85 ) Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility. The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of September 30, 2019 : Commodity Number of Units Natural gas (MMBtu) 2,018,659,087 Electricity (MWh) 30,880,332 Foreign currency exchange (CAD) 79,292,076 Various subsidiaries of DTE Energy have entered into contracts which contain ratings triggers and are guaranteed by DTE Energy. These contracts contain provisions which allow the counterparties to require that DTE Energy post cash or letters of credit as collateral in the event that DTE Energy’s credit rating is downgraded below investment grade. Certain of these provisions (known as "hard triggers") state specific circumstances under which DTE Energy can be required to post collateral upon the occurrence of a credit downgrade, while other provisions (known as "soft triggers") are not as specific. For contracts with soft triggers, it is difficult to estimate the amount of collateral which may be requested by counterparties and/or which DTE Energy may ultimately be required to post. The amount of such collateral which could be requested fluctuates based on commodity prices (primarily natural gas, power, and coal) and the provisions and maturities of the underlying transactions. As of September 30, 2019 , DTE Energy's contractual obligation to post collateral in the form of cash or letters of credit in the event of a downgrade to below investment grade, under both hard trigger and soft trigger provisions, was $517 million . As of September 30, 2019 , DTE Energy had $364 million of derivatives in net liability positions, for which hard triggers exist. There is no collateral that has been posted against such liabilities, including cash and letters of credit. Associated derivative net asset positions for which contractual offset exists were $304 million . The net remaining amount of $60 million is derived from the $517 million noted above.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT Debt Issuances In 2019 , the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric February Mortgage Bonds (a) 3.95% 2049 $ 650 DTE Energy June Senior Notes (b) 2.60% 2022 300 DTE Energy June Senior Notes (b) 3.40% 2029 500 $ 1,450 _______________________________________ (a) Bonds were issued as Green Bonds and the proceeds will be used to finance expenditures for solar and wind energy, payments under power purchase agreements for solar and wind energy, and energy optimization programs. (b) Proceeds were used for the repayment of short-term borrowings and general corporate purposes. In October 2019, DTE Gas issued $140 million of 2.95% First Mortgage Bonds due October 1, 2029 and $140 million of 3.72% First Mortgage Bonds due October 1, 2049 to a group of institutional investors in a private placement transaction. Proceeds were used for the repayment of short-term borrowings and for general corporate purposes. Additionally in October 2019, the following securities were redeemed at maturity: $400 million DTE Energy 2016 Series D 1.5% Senior Notes and $120 million DTE Gas 2004 Series E 5.0% Senior Notes. Remarketable Senior Notes In August 2019, DTE Energy remarketed the $675 million 2016 Series C 1.5% RSNs due 2024 pursuant to the terms of the 2016 Equity Units. As a result of the remarketing, the interest rate was reset to 2.529% , payable semi-annually at the new rate beginning October 1, 2019. At September 30, 2019, these securities are included in Mortgage, bonds, notes and other within DTE Energy's Consolidated Statements of Financial Position. DTE Energy did not receive any proceeds for the remarketing. All proceeds belonged to the investors holding the related 2016 Equity Units and were temporarily used to purchase a portfolio of treasury securities. The securities were released on behalf of investors to complete the related stock purchase contracts settlement date of October 1, 2019 to pay the purchase price to DTE Energy for the issuance of approximately 5.87 million shares of common stock.

Short-Term Credit Arrangements

Short-Term Credit Arrangements and Borrowings	9 Months Ended
	Sep. 30, 2019
Short-term Debt [Abstract]
Short-Term Credit Arrangements and Borrowings	SHORT-TERM CREDIT ARRANGEMENTS AND BORROWINGS DTE Energy, DTE Electric, and DTE Gas have unsecured revolving credit agreements that can be used for general corporate borrowings, but are intended to provide liquidity support for each of the companies’ commercial paper programs. Borrowings under the revolvers are available at prevailing short-term interest rates. Additionally, DTE Energy has other facilities to support letter of credit issuance. The agreements require DTE Energy, DTE Electric, and DTE Gas to maintain a total funded debt to capitalization ratio of no more than 0.65 to 1. In the agreements, "total funded debt" means all indebtedness of each respective company and their consolidated subsidiaries, including capital lease obligations, hedge agreements, and guarantees of third parties’ debt, but excluding contingent obligations, nonrecourse and junior subordinated debt, and certain equity-linked securities and, except for calculations at the end of the second quarter, certain DTE Gas short-term debt. "Capitalization" means the sum of (a) total funded debt plus (b) "consolidated net worth," which is equal to consolidated total equity of each respective company and their consolidated subsidiaries (excluding pension effects under certain FASB statements), as determined in accordance with accounting principles generally accepted in the United States of America. At September 30, 2019 , the total funded debt to total capitalization ratios for DTE Energy, DTE Electric, and DTE Gas were 0.57 to 1, 0.52 to 1, and 0.46 to 1, respectively, and were in compliance with this financial covenant. The availability under the facilities in place at September 30, 2019 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2021 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 1,760 500 300 2,560 Amounts outstanding at September 30, 2019 Commercial paper issuances 110 382 232 724 Letters of credit 191 — — 191 301 382 232 915 Net availability at September 30, 2019 $ 1,459 $ 118 $ 68 $ 1,645 In August 2019, DTE Energy increased its $70 million letter of credit facility to $110 million . The facility's maturity date was amended from September 2019 to August 2021. DTE Energy has $9 million of other outstanding letters of credit which are used for various corporate purposes and are not included in the facilities described above. In conjunction with maintaining certain exchange traded risk management positions, DTE Energy may be required to post collateral with its clearing agent. DTE Energy has a demand financing agreement for up to $100 million with its clearing agent. The agreement, as amended, also allows for up to $50 million of additional margin financing provided that DTE Energy posts a letter of credit for the incremental amount and allows the right of setoff with posted collateral. At September 30, 2019 , the capacity under this facility was $150 million . The amount outstanding under this agreement was $94 million and $93 million at September 30, 2019 and December 31, 2018 , respectively, and was fully offset by the posted collateral.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	LEASES Disclosures related to the nine months ended September 30, 2019 are presented as required under Topic 842. Prior period disclosures for the year ended December 31, 2018 are presented under Topic 840. The Registrants have elected to use a practical expedient provided by Topic 842 whereby comparative disclosures for prior periods are allowed to be presented under Topic 840. Prior period disclosures under Topic 840 have been provided on an annual basis. As a result, the disclosures presented under Topic 842 and Topic 840 will not be fully comparable in specific disclosure requirements or time period. Lessee Topic 842 — Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The components of lease cost for DTE Energy were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 10 $ 31 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost 2 8 Short-term lease cost 2 7 $ 14 $ 49 The components of lease cost for DTE Electric were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 5 $ 13 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost — — Short-term lease cost 1 2 $ 6 $ 18 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. Other information related to leases were as follows: DTE Energy DTE Electric Nine Months Ended September 30, 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows from finance leases $ 4 $ 4 Operating cash flows from operating leases $ 30 $ 11 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 37 $ 2 Weighted Average Remaining Lease Term Operating leases 9.7 years 10.6 years Finance leases 2.3 years 2.3 years Weighted Average Discount Rate Operating leases 3.7% 3.7% Finance leases 3.1% 3.1% The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8 Finance leases reported on the Consolidated Statement of Financial Position were as follows: DTE Energy DTE Electric September 30, 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 8 $ 8 Current lease liabilities, within Current Liabilities — Other $ 3 $ 3 Topic 840 — The following disclosures are presented under Topic 840 for the year ended December 31, 2018 . The Registrants lease various assets under operating leases, including coal railcars, office buildings, a warehouse, computers, vehicles, and other equipment. The lease arrangements expire at various dates through 2051 and 2046 for DTE Energy and DTE Electric, respectively. The Registrants' future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows: DTE Energy DTE Electric (In millions) 2019 $ 42 $ 17 2020 30 12 2021 18 10 2022 11 7 2023 8 5 2024 and thereafter 45 29 $ 154 $ 80 Lessor Topic 842 — DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a 20 -year finance lease contract that expires in 2020, with renewal options extending for five years each. DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has an energy services agreement that expires in 2026, of which a portion is accounted for as a finance lease. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 3 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Fixed payments $ 17 $ 51 Variable payments 40 92 $ 57 $ 143 DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of September 30, 2019 were: DTE Energy (In millions) 2019 $ 16 2020 66 2021 64 2022 22 2023 22 2024 and thereafter 216 $ 406 Depreciation expense associated with DTE Energy's property under operating leases was $7 million and $20 million for the three and nine months ended September 30, 2019 , respectively. Property under operating leases for DTE Energy was as follows: DTE Energy September 30, 2019 (In millions) Gross property under operating leases $ 444 Accumulated amortization of property under operating leases $ 166 The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2019 (In millions) 2019 $ 3 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 13 Residual value of leased pipeline 40 Less unearned income 6 Net investment in finance lease 47 Less current portion 5 $ 42 Interest income recognized under finance leases was $2 million and $4 million for the three and nine months ended September 30, 2019 , respectively. Topic 840 — DTE Energy leases various assets under operating leases for energy facilities and related equipment. DTE Energy’s minimum future rental revenues under non-cancelable operating leases as of December 31, 2018 were: DTE Energy (In millions) 2019 $ 66 2020 66 2021 64 2022 20 2023 20 2024 and thereafter 196 $ 432 The amounts listed above do not include contingent rentals associated with the leased assets. DTE Energy had contingent rental revenues of $107 million , $91 million , and $101 million in 2018, 2017, and 2016, respectively. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a capital lease contract that expires in 2020, with renewal options extending for five years . DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has two energy services agreements, for which a portion of are accounted for as capital leases. These agreements expire in 2019 and 2026. The components of DTE Energy’s net investment in capital leases at December 31, 2018 were as follows: DTE Energy (In millions) 2019 $ 10 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 20 Residual value of leased pipeline 40 Less unearned income 9 Net investment in capital lease 51 Less current portion 5 $ 46 Property under operating leases for DTE Energy as of December 31, 2018 were as follows: DTE Energy (In millions) Gross property under operating leases $ 447 Accumulated amortization of property under operating leases $ 148
Leases	LEASES Disclosures related to the nine months ended September 30, 2019 are presented as required under Topic 842. Prior period disclosures for the year ended December 31, 2018 are presented under Topic 840. The Registrants have elected to use a practical expedient provided by Topic 842 whereby comparative disclosures for prior periods are allowed to be presented under Topic 840. Prior period disclosures under Topic 840 have been provided on an annual basis. As a result, the disclosures presented under Topic 842 and Topic 840 will not be fully comparable in specific disclosure requirements or time period. Lessee Topic 842 — Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The components of lease cost for DTE Energy were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 10 $ 31 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost 2 8 Short-term lease cost 2 7 $ 14 $ 49 The components of lease cost for DTE Electric were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 5 $ 13 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost — — Short-term lease cost 1 2 $ 6 $ 18 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. Other information related to leases were as follows: DTE Energy DTE Electric Nine Months Ended September 30, 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows from finance leases $ 4 $ 4 Operating cash flows from operating leases $ 30 $ 11 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 37 $ 2 Weighted Average Remaining Lease Term Operating leases 9.7 years 10.6 years Finance leases 2.3 years 2.3 years Weighted Average Discount Rate Operating leases 3.7% 3.7% Finance leases 3.1% 3.1% The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8 Finance leases reported on the Consolidated Statement of Financial Position were as follows: DTE Energy DTE Electric September 30, 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 8 $ 8 Current lease liabilities, within Current Liabilities — Other $ 3 $ 3 Topic 840 — The following disclosures are presented under Topic 840 for the year ended December 31, 2018 . The Registrants lease various assets under operating leases, including coal railcars, office buildings, a warehouse, computers, vehicles, and other equipment. The lease arrangements expire at various dates through 2051 and 2046 for DTE Energy and DTE Electric, respectively. The Registrants' future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows: DTE Energy DTE Electric (In millions) 2019 $ 42 $ 17 2020 30 12 2021 18 10 2022 11 7 2023 8 5 2024 and thereafter 45 29 $ 154 $ 80 Lessor Topic 842 — DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a 20 -year finance lease contract that expires in 2020, with renewal options extending for five years each. DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has an energy services agreement that expires in 2026, of which a portion is accounted for as a finance lease. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 3 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Fixed payments $ 17 $ 51 Variable payments 40 92 $ 57 $ 143 DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of September 30, 2019 were: DTE Energy (In millions) 2019 $ 16 2020 66 2021 64 2022 22 2023 22 2024 and thereafter 216 $ 406 Depreciation expense associated with DTE Energy's property under operating leases was $7 million and $20 million for the three and nine months ended September 30, 2019 , respectively. Property under operating leases for DTE Energy was as follows: DTE Energy September 30, 2019 (In millions) Gross property under operating leases $ 444 Accumulated amortization of property under operating leases $ 166 The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2019 (In millions) 2019 $ 3 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 13 Residual value of leased pipeline 40 Less unearned income 6 Net investment in finance lease 47 Less current portion 5 $ 42 Interest income recognized under finance leases was $2 million and $4 million for the three and nine months ended September 30, 2019 , respectively. Topic 840 — DTE Energy leases various assets under operating leases for energy facilities and related equipment. DTE Energy’s minimum future rental revenues under non-cancelable operating leases as of December 31, 2018 were: DTE Energy (In millions) 2019 $ 66 2020 66 2021 64 2022 20 2023 20 2024 and thereafter 196 $ 432 The amounts listed above do not include contingent rentals associated with the leased assets. DTE Energy had contingent rental revenues of $107 million , $91 million , and $101 million in 2018, 2017, and 2016, respectively. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a capital lease contract that expires in 2020, with renewal options extending for five years . DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has two energy services agreements, for which a portion of are accounted for as capital leases. These agreements expire in 2019 and 2026. The components of DTE Energy’s net investment in capital leases at December 31, 2018 were as follows: DTE Energy (In millions) 2019 $ 10 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 20 Residual value of leased pipeline 40 Less unearned income 9 Net investment in capital lease 51 Less current portion 5 $ 46 Property under operating leases for DTE Energy as of December 31, 2018 were as follows: DTE Energy (In millions) Gross property under operating leases $ 447 Accumulated amortization of property under operating leases $ 148
Leases	LEASES Disclosures related to the nine months ended September 30, 2019 are presented as required under Topic 842. Prior period disclosures for the year ended December 31, 2018 are presented under Topic 840. The Registrants have elected to use a practical expedient provided by Topic 842 whereby comparative disclosures for prior periods are allowed to be presented under Topic 840. Prior period disclosures under Topic 840 have been provided on an annual basis. As a result, the disclosures presented under Topic 842 and Topic 840 will not be fully comparable in specific disclosure requirements or time period. Lessee Topic 842 — Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The components of lease cost for DTE Energy were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 10 $ 31 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost 2 8 Short-term lease cost 2 7 $ 14 $ 49 The components of lease cost for DTE Electric were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 5 $ 13 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost — — Short-term lease cost 1 2 $ 6 $ 18 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. Other information related to leases were as follows: DTE Energy DTE Electric Nine Months Ended September 30, 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows from finance leases $ 4 $ 4 Operating cash flows from operating leases $ 30 $ 11 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 37 $ 2 Weighted Average Remaining Lease Term Operating leases 9.7 years 10.6 years Finance leases 2.3 years 2.3 years Weighted Average Discount Rate Operating leases 3.7% 3.7% Finance leases 3.1% 3.1% The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8 Finance leases reported on the Consolidated Statement of Financial Position were as follows: DTE Energy DTE Electric September 30, 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 8 $ 8 Current lease liabilities, within Current Liabilities — Other $ 3 $ 3 Topic 840 — The following disclosures are presented under Topic 840 for the year ended December 31, 2018 . The Registrants lease various assets under operating leases, including coal railcars, office buildings, a warehouse, computers, vehicles, and other equipment. The lease arrangements expire at various dates through 2051 and 2046 for DTE Energy and DTE Electric, respectively. The Registrants' future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows: DTE Energy DTE Electric (In millions) 2019 $ 42 $ 17 2020 30 12 2021 18 10 2022 11 7 2023 8 5 2024 and thereafter 45 29 $ 154 $ 80 Lessor Topic 842 — DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a 20 -year finance lease contract that expires in 2020, with renewal options extending for five years each. DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has an energy services agreement that expires in 2026, of which a portion is accounted for as a finance lease. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 3 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Fixed payments $ 17 $ 51 Variable payments 40 92 $ 57 $ 143 DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of September 30, 2019 were: DTE Energy (In millions) 2019 $ 16 2020 66 2021 64 2022 22 2023 22 2024 and thereafter 216 $ 406 Depreciation expense associated with DTE Energy's property under operating leases was $7 million and $20 million for the three and nine months ended September 30, 2019 , respectively. Property under operating leases for DTE Energy was as follows: DTE Energy September 30, 2019 (In millions) Gross property under operating leases $ 444 Accumulated amortization of property under operating leases $ 166 The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2019 (In millions) 2019 $ 3 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 13 Residual value of leased pipeline 40 Less unearned income 6 Net investment in finance lease 47 Less current portion 5 $ 42 Interest income recognized under finance leases was $2 million and $4 million for the three and nine months ended September 30, 2019 , respectively. Topic 840 — DTE Energy leases various assets under operating leases for energy facilities and related equipment. DTE Energy’s minimum future rental revenues under non-cancelable operating leases as of December 31, 2018 were: DTE Energy (In millions) 2019 $ 66 2020 66 2021 64 2022 20 2023 20 2024 and thereafter 196 $ 432 The amounts listed above do not include contingent rentals associated with the leased assets. DTE Energy had contingent rental revenues of $107 million , $91 million , and $101 million in 2018, 2017, and 2016, respectively. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a capital lease contract that expires in 2020, with renewal options extending for five years . DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has two energy services agreements, for which a portion of are accounted for as capital leases. These agreements expire in 2019 and 2026. The components of DTE Energy’s net investment in capital leases at December 31, 2018 were as follows: DTE Energy (In millions) 2019 $ 10 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 20 Residual value of leased pipeline 40 Less unearned income 9 Net investment in capital lease 51 Less current portion 5 $ 46 Property under operating leases for DTE Energy as of December 31, 2018 were as follows: DTE Energy (In millions) Gross property under operating leases $ 447 Accumulated amortization of property under operating leases $ 148
Leases	LEASES Disclosures related to the nine months ended September 30, 2019 are presented as required under Topic 842. Prior period disclosures for the year ended December 31, 2018 are presented under Topic 840. The Registrants have elected to use a practical expedient provided by Topic 842 whereby comparative disclosures for prior periods are allowed to be presented under Topic 840. Prior period disclosures under Topic 840 have been provided on an annual basis. As a result, the disclosures presented under Topic 842 and Topic 840 will not be fully comparable in specific disclosure requirements or time period. Lessee Topic 842 — Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The components of lease cost for DTE Energy were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 10 $ 31 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost 2 8 Short-term lease cost 2 7 $ 14 $ 49 The components of lease cost for DTE Electric were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 5 $ 13 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost — — Short-term lease cost 1 2 $ 6 $ 18 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. Other information related to leases were as follows: DTE Energy DTE Electric Nine Months Ended September 30, 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows from finance leases $ 4 $ 4 Operating cash flows from operating leases $ 30 $ 11 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 37 $ 2 Weighted Average Remaining Lease Term Operating leases 9.7 years 10.6 years Finance leases 2.3 years 2.3 years Weighted Average Discount Rate Operating leases 3.7% 3.7% Finance leases 3.1% 3.1% The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8 Finance leases reported on the Consolidated Statement of Financial Position were as follows: DTE Energy DTE Electric September 30, 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 8 $ 8 Current lease liabilities, within Current Liabilities — Other $ 3 $ 3 Topic 840 — The following disclosures are presented under Topic 840 for the year ended December 31, 2018 . The Registrants lease various assets under operating leases, including coal railcars, office buildings, a warehouse, computers, vehicles, and other equipment. The lease arrangements expire at various dates through 2051 and 2046 for DTE Energy and DTE Electric, respectively. The Registrants' future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows: DTE Energy DTE Electric (In millions) 2019 $ 42 $ 17 2020 30 12 2021 18 10 2022 11 7 2023 8 5 2024 and thereafter 45 29 $ 154 $ 80 Lessor Topic 842 — DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a 20 -year finance lease contract that expires in 2020, with renewal options extending for five years each. DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has an energy services agreement that expires in 2026, of which a portion is accounted for as a finance lease. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 3 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Fixed payments $ 17 $ 51 Variable payments 40 92 $ 57 $ 143 DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of September 30, 2019 were: DTE Energy (In millions) 2019 $ 16 2020 66 2021 64 2022 22 2023 22 2024 and thereafter 216 $ 406 Depreciation expense associated with DTE Energy's property under operating leases was $7 million and $20 million for the three and nine months ended September 30, 2019 , respectively. Property under operating leases for DTE Energy was as follows: DTE Energy September 30, 2019 (In millions) Gross property under operating leases $ 444 Accumulated amortization of property under operating leases $ 166 The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2019 (In millions) 2019 $ 3 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 13 Residual value of leased pipeline 40 Less unearned income 6 Net investment in finance lease 47 Less current portion 5 $ 42 Interest income recognized under finance leases was $2 million and $4 million for the three and nine months ended September 30, 2019 , respectively. Topic 840 — DTE Energy leases various assets under operating leases for energy facilities and related equipment. DTE Energy’s minimum future rental revenues under non-cancelable operating leases as of December 31, 2018 were: DTE Energy (In millions) 2019 $ 66 2020 66 2021 64 2022 20 2023 20 2024 and thereafter 196 $ 432 The amounts listed above do not include contingent rentals associated with the leased assets. DTE Energy had contingent rental revenues of $107 million , $91 million , and $101 million in 2018, 2017, and 2016, respectively. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a capital lease contract that expires in 2020, with renewal options extending for five years . DTE Energy owns a 40% interest in the Vector Pipeline. In addition, DTE Energy has two energy services agreements, for which a portion of are accounted for as capital leases. These agreements expire in 2019 and 2026. The components of DTE Energy’s net investment in capital leases at December 31, 2018 were as follows: DTE Energy (In millions) 2019 $ 10 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 20 Residual value of leased pipeline 40 Less unearned income 9 Net investment in capital lease 51 Less current portion 5 $ 46 Property under operating leases for DTE Energy as of December 31, 2018 were as follows: DTE Energy (In millions) Gross property under operating leases $ 447 Accumulated amortization of property under operating leases $ 148

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Environmental DTE Electric Air — DTE Electric is subject to the EPA ozone and fine particulate transport and acid rain regulations that limit power plant emissions of SO 2 and NO X . The EPA and the State of Michigan have also issued emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to controls on fossil-fueled power plants to reduce SO 2 , NO X , mercury, and other emissions. Additional rulemakings may occur over the next few years which could require additional controls for SO 2 , NO X , and other hazardous air pollutants. The EPA proposed revised air quality standards for ground level ozone in November 2014 and specifically requested comments on the form and level of the ozone standards. The standards were finalized in October 2015. The State of Michigan recommended to the EPA in October 2016 which areas of the state are not attaining the new standard. On April 30, 2018, the EPA finalized the State of Michigan's recommended marginal non-attainment designation for southeast Michigan. The State is required to develop and implement a plan to address the southeast Michigan ozone non-attainment area by 2021. The Registrants cannot predict the financial impact of the State's plan to address the ozone non-attainment area at this time. In July 2009, the Registrants received a NOV/FOV from the EPA alleging, among other things, that five DTE Electric power plants violated New Source Performance standards, Prevention of Significant Deterioration requirements, and operating permit requirements under the Clean Air Act. In June 2010, the EPA issued a NOV/FOV making similar allegations related to a project and outage at Unit 2 of the Monroe Power Plant. In March 2013, DTE Energy received a supplemental NOV from the EPA relating to the July 2009 NOV/FOV. The supplemental NOV alleged additional violations relating to the New Source Review provisions under the Clean Air Act, among other things. In August 2010, the U.S. Department of Justice, at the request of the EPA, brought a civil suit in the U.S. District Court for the Eastern District of Michigan against DTE Energy and DTE Electric, related to the June 2010 NOV/FOV and the outage work performed at Unit 2 of the Monroe Power Plant. In August 2011, the U.S. District Court judge granted DTE Energy's motion for summary judgment in the civil case, dismissing the case and entering judgment in favor of DTE Energy and DTE Electric. In October 2011, the EPA filed a Notice of Appeal to the Court of Appeals for the Sixth Circuit. In March 2013, the Court of Appeals remanded the case to the U.S. District Court for review of the procedural component of the New Source Review notification requirements. In September 2013, the EPA filed a motion seeking leave to amend their complaint regarding the June 2010 NOV/FOV adding additional claims related to outage work performed at the Trenton Channel and Belle River Power Plants as well as additional claims related to work performed at the Monroe Power Plant. In March 2014, the U.S. District Court judge again granted DTE Energy's motion for summary judgment dismissing the civil case related to Monroe Unit 2. In April 2014, the U.S. District Court judge granted motions filed by the EPA and the Sierra Club to amend their New Source Review complaint adding additional claims for Monroe Units 1, 2, and 3, Belle River Units 1 and 2, and Trenton Channel Unit 9. In October 2014, the EPA and the U.S. Department of Justice filed a notice of appeal of the U.S. District Court judge's dismissal of the Monroe Unit 2 case. The amended New Source Review claims were all stayed pending resolution of the appeal by the Court of Appeals for the Sixth Circuit. On January 10, 2017, a divided panel of the Court reversed the decision of the U.S. District Court. On May 8, 2017, DTE Energy and DTE Electric filed a motion to stay the mandate pending filing of a petition for writ of certiorari with the U.S. Supreme Court. The Sixth Circuit granted the motion on May 16, 2017, staying the claims in the U.S. District Court until the U.S. Supreme Court disposes of the case. DTE Electric and DTE Energy filed a petition for writ of certiorari on July 31, 2017. On December 11, 2017, the U.S. Supreme Court denied certiorari. As a result of the Supreme Court electing not to review the matter, the case was sent back to the U.S. District Court for further proceedings and on June 14, 2018 the case was stayed pending settlement negotiations. The proceedings at the District Court remain stayed while the parties discuss potential resolution of the matter. The Registrants believe that the plants and generating units identified by the EPA and the Sierra Club have complied with all applicable federal environmental regulations. Depending upon the outcome of the litigation and further discussions with the EPA regarding the two NOVs/FOVs, DTE Electric could be required to install additional pollution control equipment at some or all of the power plants in question, implement early retirement of facilities where control equipment is not economical, engage in supplemental environmental programs, and/or pay fines. The Registrants do not expect the outcome for this matter to have a material impact on their Consolidated Financial Statements. The EPA has implemented regulatory actions under the Clean Air Act to address emissions of GHGs from the utility sector and other sectors of the economy. Among these actions, in 2015 the EPA finalized performance standards for emissions of carbon dioxide from new and existing fossil-fuel fired EGUs. The performance standards for existing EGUs, known as the EPA Clean Power Plan, were challenged by petitioners and stayed by the U.S. Supreme Court in February 2016 pending final review by the courts. On October 10, 2017, the EPA, under a new administration, proposed to rescind the Clean Power Plan, and in August 2018, the EPA proposed revised emission guidelines for GHGs from existing EGUs. On June 19, 2019, the EPA Administrator officially repealed the Clean Power Plan and finalized its replacement, named the Affordable Clean Energy (ACE) rule. These final rules do not impact DTE Energy's revised commitment to reduce carbon emissions 32% by the early 2020 s, 50% by 2030 , and 80% by 2040 , or its goal of net zero emissions by 2050 for DTE Electric, from the 2005 carbon emissions levels. In addition to the GHG standards for existing EGUs, in December 2018, the EPA issued proposed revisions to the carbon dioxide performance standards for new, modified, or reconstructed fossil-fuel fired EGUs. The carbon standards for new sources are not expected to have a material impact on DTE Electric, since DTE Electric has no plans to build new coal-fired generation and any potential new gas generation will be able to comply with the standards. Pending or future legislation or other regulatory actions could have a material impact on DTE Electric's operations and financial position and the rates charged to its customers. Impacts include expenditures for environmental equipment beyond what is currently planned, financing costs related to additional capital expenditures, the purchase of emission credits from market sources, higher costs of purchased power, and the retirement of facilities where control equipment is not economical. DTE Electric would seek to recover these incremental costs through increased rates charged to its utility customers, as authorized by the MPSC. To comply with air pollution requirements, DTE Electric spent approximately $2.4 billion through 2018 . DTE Electric does not anticipate additional capital expenditures for air pollution requirements through 2025 . Water — In response to an EPA regulation, DTE Electric was required to examine alternatives for reducing the environmental impacts of the cooling water intake structures at several of its facilities. Based on the results of completed studies and expected future studies, DTE Electric may be required to install technologies to reduce the impacts of the water intake structures. A final rule became effective in October 2014. The final rule requires studies to be completed and submitted as part of the National Pollutant Discharge Elimination System (NPDES) permit application process to determine the type of technology needed to reduce impacts to fish. DTE Electric has initiated the process of completing the required studies. Final compliance for the installation of any required technology will be determined by the state on a case by case, site specific basis. DTE Electric is currently evaluating the compliance options and working with the State of Michigan on evaluating whether any controls are needed. These evaluations/studies may require modifications to some existing intake structures. It is not possible to quantify the impact of this rulemaking at this time. Contaminated and Other Sites — Prior to the construction of major interstate natural gas pipelines, gas for heating and other uses was manufactured locally from processes involving coal, coke, or oil. The facilities, which produced gas, have been designated as MGP sites. DTE Electric conducted remedial investigations at contaminated sites, including three former MGP sites. The investigations have revealed contamination related to the by-products of gas manufacturing at each MGP site. In addition to the MGP sites, DTE Electric is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and aboveground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At September 30, 2019 and December 31, 2018 , DTE Electric had $8 million and $7 million , respectively, accrued for remediation. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Electric’s financial position and cash flows. DTE Electric believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site. Coal Combustion Residuals and Effluent Limitations Guidelines — A final EPA rule for the disposal of coal combustion residuals, commonly known as coal ash, became effective in October 2015, and was revised in October 2016 and July 2018. Additionally, D.C. District Court Decisions on August 21, 2018 and March 19, 2019 may affect the timing of closure of coal ash impoundments that are not lined with an engineered liner system. In late 2019, the EPA is expected to affirmatively undertake rulemaking to implement the D.C. District Court's decisions that will determine any changes to DTE Electric's plans in the operation and closure of coal ash impoundments. At the State level, legislation was signed by the Governor in December 2018 and provides for further regulation of the CCR program in Michigan. Additionally, the bill provides the basis of a CCR program that EGLE will submit to the EPA for approval to fully regulate the CCR program in Michigan in lieu of a Federal permit program. DTE Electric owns and operates three permitted engineered coal ash storage facilities to dispose of coal ash from coal-fired power plants and operates a number of smaller impoundments at its power plants. CCR obligations vary based on plant life, but include the installation of monitoring wells, compliance with groundwater standards, and the closure of landfills and basins at the end of the useful life of the associated power plant unless closure is triggered by a specific CCR rule requirement. Under the current CCR rules and uncertainty regarding the outcome of the D.C. District Court decision to remand portions of the rule to the EPA, capital costs and timing associated with the building of new CCR facilities or retirement of existing CCR facilities are being evaluated. In November 2015, the EPA finalized the ELG Rule for the steam electric power generating industry which requires additional controls to be installed between 2018 and 2023. Compliance schedules for individual facilities and individual waste streams are determined through issuance of new National Pollutant Discharge Elimination System (NPDES) permits by the State of Michigan. The State of Michigan has issued a NPDES permit for the Belle River Power Plant establishing a compliance deadline of December 31, 2021. No new permits that would require ELG compliance have been issued for other facilities, consequently no compliance timelines have been established. On April 12, 2017, the EPA granted a petition for reconsideration of the ELG Rule. The EPA also signed an administrative stay of the ELG Rule’s compliance deadlines for fly ash transport water, bottom ash transport water, and flue gas desulfurization (FGD) wastewater, among others. On June 6, 2017, the EPA published in the Federal Register a proposed rule (Postponement Rule) to postpone certain applicable deadlines within the 2015 ELG rule. The Postponement Rule was published on September 18, 2017. The Postponement Rule nullified the administrative stay but also extended the earliest compliance deadlines for only FGD wastewater and bottom ash transport water until November 1, 2020 in order for the EPA to propose and finalize a new ruling. The ELG compliance requirements and final deadlines for bottom ash transport water and FGD wastewater, and total ELG related compliance costs will not be known until the EPA completes its reconsideration of the ELG Rule expected by the end of 2020. DTE Gas Contaminated and Other Sites — DTE Gas owns or previously owned, 14 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of eight of the MGP sites is complete, and the sites are closed. DTE Gas has also completed partial closure of four additional sites. Cleanup activities associated with the remaining sites will continue over the next several years. The MPSC has established a cost deferral and rate recovery mechanism for investigation and remediation costs incurred at former MGP sites. In addition to the MGP sites, DTE Gas is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases, and underground storage tank locations. As of September 30, 2019 and December 31, 2018 , DTE Gas had $25 million accrued for remediation. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Gas' financial position and cash flows. DTE Gas anticipates the cost amortization methodology approved by the MPSC, which allows for amortization of the MGP costs over a ten -year period beginning with the year subsequent to the year the MGP costs were incurred, will prevent environmental costs from having a material adverse impact on DTE Gas' results of operations. Non-utility DTE Energy's non-utility businesses are subject to a number of environmental laws and regulations dealing with the protection of the environment from various pollutants. In March 2019, the EPA issued a finding of violation to EES Coke, the Michigan coke battery facility that is a wholly-owned subsidiary of DTE Energy, alleging that the 2008 and 2014 permits issued by EGLE did not comply with the Clean Air Act. EES Coke evaluated the EPA's alleged violations and believes that the permits approved by EGLE complied with the Clean Air Act. Discussions with the EPA are ongoing. At the present time, DTE Energy does not believe this will have a material financial impact. Other In 2010, the EPA finalized a new one -hour SO 2 ambient air quality standard that requires states to submit plans and associated timelines for non-attainment areas that demonstrate attainment with the new SO 2 standard in phases. Phase 1 addresses non-attainment areas designated based on ambient monitoring data. Phase 2 addresses non-attainment areas with large sources of SO 2 and modeled concentrations exceeding the National Ambient Air Quality Standards for SO 2 . Phase 3 addresses smaller sources of SO 2 with modeled or monitored exceedances of the new SO 2 standard. Michigan's Phase 1 non-attainment area includes DTE Energy facilities in southwest Detroit and areas of Wayne County. Modeling runs by EGLE suggest that emission reductions may be required by significant sources of SO 2 emissions in these areas, including DTE Electric power plants and DTE Energy's Michigan coke battery facility. As part of the state implementation plan process, DTE Energy has worked with EGLE to develop air permits reflecting significant SO 2 emission reductions that, in combination with other non-DTE Energy sources' emission reduction strategies, will help the state attain the standard and sustain its attainment. Since several non-DTE Energy sources are also part of the proposed compliance plan, DTE Energy is unable to determine the full impact of the final required emissions reductions at this time. Michigan's Phase 2 non-attainment area includes DTE Electric facilities in St. Clair County. State implementation plan (SIP) submittal and EPA approval describing the control strategy and timeline for demonstrating compliance with the new SO 2 standard is the next step in the process and is expected to be completed by the end of 2019. DTE Energy is currently working with EGLE to develop the required SIP. DTE Energy is unable to determine the full impact of the SIP strategy. Synthetic Fuel Guarantees DTE Energy discontinued the operations of its synthetic fuel production facilities throughout the United States as of December 31, 2007. DTE Energy provided certain guarantees and indemnities in conjunction with the sales of interests in its synfuel facilities. The guarantees cover potential commercial, environmental, oil price, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at September 30, 2019 was approximately $400 million . Payment under these guarantees are considered remote. REF Guarantees DTE Energy has provided certain guarantees and indemnities in conjunction with the sales of interests in or lease of its REF facilities. The guarantees cover potential commercial, environmental, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at September 30, 2019 was $491 million . Payments under these guarantees are considered remote. NEXUS Guarantees NEXUS entered into certain 15 -year capacity agreements for the transportation of natural gas with DTE Gas and Texas Eastern Transmission, LP, an unrelated third party. Pursuant to the terms of those agreements, in December 2016, DTE Energy executed separate guarantee agreements with DTE Gas and Texas Eastern Transmission, LP, with maximum potential payments totaling $242 million and $377 million at September 30, 2019 , respectively; each representing 50% of all payment obligations due and payable by NEXUS. Each guarantee terminates at the earlier of (i) such time as all of the guaranteed obligations have been fully performed, or (ii) two months following the end of the primary term of the capacity agreements. In October 2018, NEXUS Pipeline was placed in service. The amount of each guarantee decreases annually as payments are made by NEXUS to each of the aforementioned counterparties. NEXUS also entered into certain 15 -year capacity agreements for the transportation of natural gas with Vector, an equity method investee of DTE Energy. Pursuant to the terms of those agreements, in October 2018, DTE Energy executed a guarantee agreement with Vector, with a maximum potential payment totaling $7 million at September 30, 2019 , representing 50% of the first-year payment obligations due and payable by NEXUS. The guarantee terminates at the earlier of (i) such time as all of the guaranteed obligations have been fully performed or (ii) 15 years from the date DTE Energy entered into the guarantee. Should NEXUS fail to perform under the terms of these agreements, DTE Energy is required to perform on its behalf. Payments under these guarantees are considered remote. Other Guarantees In certain limited circumstances, the Registrants enter into contractual guarantees. The Registrants may guarantee another entity’s obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. Finally, the Registrants may provide indirect guarantees for the indebtedness of others. DTE Energy’s guarantees are not individually material with maximum potential payments totaling $56 million at September 30, 2019 . Payments under these guarantees are considered remote. DTE Energy is periodically required to obtain performance surety bonds in support of obligations to various governmental entities and other companies in connection with its operations. As of September 30, 2019 , DTE Energy had $108 million of performance bonds outstanding. In the event that such bonds are called for nonperformance, DTE Energy would be obligated to reimburse the issuer of the performance bond. DTE Energy is released from the performance bonds as the contractual performance is completed and does not believe that a material amount of any currently outstanding performance bonds will be called. Vector Line of Credit In July 2019, DTE Energy, as lender, entered into a revolving term credit facility with Vector, as borrower, in the amount of C$70 million . The credit facility was executed in response to the passage of Canadian regulations requiring oil and gas pipelines to demonstrate their financial ability to respond to a catastrophic event and exists for the sole purpose of satisfying these regulations. Vector may only draw upon the facility if the funds are required to respond to a catastrophic event. The maximum potential payments under the line of credit at September 30, 2019 is $53 million . The funding of a loan under the terms of the credit facility is considered remote. Labor Contracts There are several bargaining units for DTE Energy subsidiaries' approximate 5,200 represented employees, including DTE Electric's approximate 2,800 represented employees. The majority of the represented employees are under contracts that expire in 2020 and 2021. Purchase Commitments Utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees will be approximately $5.9 billion and $2.2 billion in 2019 for DTE Energy and DTE Electric, respectively. The Registrants have made certain commitments in connection with the estimated 2019 annual capital expenditures and contributions to equity method investees. Bankruptcies DTE Energy's Power and Industrial Projects segment holds ownership interests in, and operates, five generating plants that sell electric output from renewable sources under long-term power purchase agreements with PG&E. PG&E filed for Chapter 11 bankruptcy protection on January 29, 2019. As of September 30, 2019 , PG&E's account is substantially current and outstanding accounts receivable from PG&E are not material. Therefore, DTE Energy determined no reserve was necessary. As of September 30, 2019 , the book value of long-lived assets used in producing electric output for sale to PG&E was approximately $102 million . The Power and Industrial Projects segment also has equity investments, including a note receivable, of approximately $72 million in entities that sell power to PG&E. In January 2019, following the bankruptcy filing, DTE Energy performed an impairment analysis on its long-lived assets. Based on its undiscounted cash flow projections, DTE Energy determined it did no t have an impairment loss as of December 31, 2018. DTE Energy also determined there was no t an other-than-temporary decline in its equity investments. There were no other new events occurring during the nine months ended September 30, 2019 , that would negatively impact the assumptions made within the December 31, 2018 impairment analysis. Therefore, no triggering events were identified. DTE Energy's assumptions and conclusions may change, and it could have impairment losses if any of the terms of the contracts are not honored by PG&E or the contracts are rejected through the bankruptcy process. Other Contingencies The Registrants are involved in certain other legal, regulatory, administrative, and environmental proceedings before various courts, arbitration panels, and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Registrants cannot predict the final disposition of such proceedings. The Registrants regularly review legal matters and record provisions for claims that they can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Registrants' Consolidated Financial Statements in the periods they are resolved. For a discussion of contingencies related to regulatory matters and derivatives, see Notes 6 and 9 to the Consolidated Financial Statements, " Regulatory Matters " and " Financial and Other Derivative Instruments ," respectively.

Retirement Benefits and Trustee

Retirement Benefits and Trusteed Assets	9 Months Ended
	Sep. 30, 2019
Defined Benefit Plan [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended September 30, 2019 2018 2019 2018 (In millions) Service cost $ 21 $ 24 $ 5 $ 6 Interest cost 55 51 18 18 Expected return on plan assets (82 ) (82 ) (30 ) (36 ) Amortization of: Net actuarial loss 33 43 3 3 Prior service credit — — (3 ) — Net periodic benefit cost (credit) $ 27 $ 36 $ (7 ) $ (9 ) Pension Benefits Other Postretirement Benefits Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Service cost $ 63 $ 74 $ 16 $ 20 Interest cost 164 151 53 52 Expected return on plan assets (244 ) (247 ) (92 ) (107 ) Amortization of: Net actuarial loss 99 132 9 8 Prior service credit — — (7 ) — Net periodic benefit cost (credit) $ 82 $ 110 $ (21 ) $ (27 ) DTE Electric participates in various plans that provide pension and other postretirement benefits for DTE Energy and its affiliates. The plans are sponsored by DTE Energy's subsidiary, DTE Energy Corporate Services, LLC. DTE Electric accounts for its participation in DTE Energy's qualified and nonqualified pension plans by applying multiemployer accounting. DTE Electric accounts for its participation in other postretirement benefit plans by applying multiple-employer accounting. Within multiemployer and multiple-employer plans, participants pool plan assets for investment purposes and to reduce the cost of plan administration. The primary difference between plan types is assets contributed in multiemployer plans can be used to provide benefits for all participating employers, while assets contributed within a multiple-employer plan are restricted for use by the contributing employer. As a result of multiemployer accounting treatment, capitalized costs associated with these plans are reflected in Property, plant, and equipment in DTE Electric's Consolidated Statements of Financial Position. The same capitalized costs are reflected as Regulatory assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. In addition, the service cost and non-service cost components are presented in Operation and maintenance in DTE Electric's Consolidated Statements of Operations. The same non-service cost components are presented in Other (Income) and Deductions — Non-operating retirement benefits, net in DTE Energy's Consolidated Statements of Operations. Plan participants of all plans are solely DTE Energy and affiliate participants. DTE Energy's subsidiaries are responsible for their share of qualified and nonqualified pension benefit costs. DTE Electric's allocated portion of pension benefit costs included in capital expenditures and operating and maintenance expense were $23 million and $30 million for the three months ended September 30, 2019 and 2018 , respectively, and $68 million and $90 million for the nine months ended September 30, 2019 and 2018 , respectively. These amounts include recognized contractual termination benefit charges, curtailment gains, and settlement charges. The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Other Postretirement Benefits Three Months Ended September 30, 2019 2018 (In millions) Service cost $ 4 $ 5 Interest cost 13 13 Expected return on plan assets (21 ) (25 ) Amortization of: Net actuarial loss 1 3 Prior service credit (1 ) — Net periodic benefit credit $ (4 ) $ (4 ) Other Postretirement Benefits Nine Months Ended September 30, 2019 2018 (In millions) Service cost $ 12 $ 15 Interest cost 40 40 Expected return on plan assets (63 ) (74 ) Amortization of: Net actuarial loss 3 7 Prior service credit (5 ) — Net periodic benefit credit $ (13 ) $ (12 ) Pension and Other Postretirement Contributions During 2019 , DTE Energy contributed the following amounts of DTE Energy common stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust: Date Number of Shares Price per Share Amount (In millions) March 5, 2019 814,597 $ 122.76 $ 100 The above contribution was made on behalf of DTE Electric, for which DTE Electric paid DTE Energy cash consideration of $100 million in March 2019. DTE Energy made cash contributions of $50 million to the qualified pension plans in the first nine months of 2019 . DTE Energy does no t anticipate making any additional contributions to its pension or other postretirement benefit plans in 2019 .

Segment and Related Information

Segment and Related Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment and Related Information	SEGMENT AND RELATED INFORMATION DTE Energy sets strategic goals, allocates resources, and evaluates performance based on the following structure: Electric segment consists principally of DTE Electric, which is engaged in the generation, purchase, distribution, and sale of electricity to approximately 2.2 million residential, commercial, and industrial customers in southeastern Michigan. Gas segment consists principally of DTE Gas, which is engaged in the purchase, storage, transportation, distribution, and sale of natural gas to approximately 1.3 million residential, commercial, and industrial customers throughout Michigan and the sale of storage and transportation capacity. Gas Storage and Pipelines is primarily engaged in services related to the gathering, transportation, and storage of natural gas. Power and Industrial Projects is comprised primarily of projects that deliver energy and utility-type products and services to industrial, commercial, and institutional customers, produce reduced emissions fuel, and sell electricity and pipeline-quality gas from renewable energy projects. Energy Trading consists of energy marketing and trading operations. Corporate and Other includes various holding company activities, holds certain non-utility debt, and holds energy-related investments. The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company. Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Electric $ 16 $ 13 $ 43 $ 39 Gas 3 3 8 9 Gas Storage and Pipelines 11 7 17 29 Power and Industrial Projects 160 171 462 488 Energy Trading 4 6 16 18 Corporate and Other 1 1 2 2 $ 195 $ 201 $ 548 $ 585 Financial data of DTE Energy's business segments follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Operating Revenues — Utility operations Electric $ 1,520 $ 1,521 $ 3,945 $ 4,002 Gas 155 164 1,043 969 Operating Revenues — Non-utility operations Gas Storage and Pipelines 126 122 363 363 Power and Industrial Projects 406 612 1,196 1,717 Energy Trading 1,105 1,332 3,519 3,994 Corporate and Other 2 — 3 2 Reconciliation and Eliminations (195 ) (201 ) (548 ) (585 ) Total $ 3,119 $ 3,550 $ 9,521 $ 10,462 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 307 $ 305 $ 587 $ 608 Gas (38 ) (30 ) 121 88 Gas Storage and Pipelines 60 66 158 188 Power and Industrial Projects 49 58 104 146 Energy Trading (14 ) (13 ) 12 13 Corporate and Other (45 ) (52 ) (80 ) (114 ) Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENT During October 2019, DTE Energy entered into an agreement with Momentum Midstream and Indigo Natural Resources to purchase midstream natural gas assets in support of its strategy to continue to grow and earn competitive returns for shareholders. The agreement calls for DTE Energy to acquire 100 percent of M5 Louisiana Gathering, LLC and its wholly owned subsidiaries which provide natural gas gathering and other midstream services to producers, primarily in Louisiana. The acquisition has an estimated purchase price of $2.65 billion and is expected to close in December 2019, subject to customary closing conditions. The purchase price includes $2.25 billion to be paid in cash upon closing, plus an estimated $400 million milestone payment upon completion of a gathering pipeline in the second half of 2020. These assets will be a part of DTE Energy’s non-utility Gas Storage and Pipelines business. The acquisition will be financed through the issuance of Equity Units, common stock, and Senior Notes. Upon closing, DTE Energy will obtain control over and apply acquisition accounting to the acquired entities, including disclosure of amounts recognized for the major classes of assets and liabilities acquired. DTE Energy will include all required information within the combined DTE Energy and DTE Electric Annual Report on Form 10-K for the year ending December 31, 2019.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2018 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions, include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2019 . The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself.
Reclassification	Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation.
Principles of Consolidation	Principles of Consolidation The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to significantly influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are generally accounted for under the equity method. DTE Energy currently owns an 85% interest in SGG, which owns and operates midstream natural gas assets. SGG has contracts through which certain construction risk is designed to pass-through to the customers, with DTE Energy retaining operational and customer default risk. SGG is a VIE with DTE Energy as the primary beneficiary. The Registrants have variable interests in NEXUS, which include DTE Energy's 50% ownership interest and DTE Electric's transportation services contract. NEXUS is a joint venture which owns a 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. NEXUS also owns Generation Pipeline, LLC, a 23-mile regulated pipeline system located in northern Ohio, which was acquired in September 2019. Refer to Note 4 , " Acquisitions ," for additional information. NEXUS is a VIE as it has insufficient equity at risk to finance its activities. The Registrants are not the primary beneficiaries, as the power to direct significant activities is shared between the owners of the equity interests. DTE Energy accounts for its ownership interest in NEXUS under the equity method. The Registrants hold ownership interests in certain limited partnerships. The limited partnerships include investment funds which support regional development and economic growth, as well as, an operational business providing energy-related products. These entities are generally VIEs as a result of certain characteristics of the limited partnership voting rights. The ownership interests are accounted for under the equity method as the Registrants are not the primary beneficiaries. DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of September 30, 2019 , the carrying amount of assets and liabilities in DTE Energy's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase and sale contracts are predominantly related to working capital accounts and generally represent the amounts owed by or to DTE Energy for the deliveries associated with the current billing cycle under the contracts. As of September 30, 2019 , the carrying amount of assets and liabilities in DTE Electric's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominantly related to working capital accounts and generally represent the amounts owed by DTE Electric for the deliveries associated with the current billing cycle under the contracts. The Registrants have not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase contracts. The maximum risk exposure for consolidated VIEs is reflected on the Registrants' Consolidated Statements of Financial Position and, for DTE Energy, in Note 13 to the Consolidated Financial Statements, " Commitments and Contingencies ," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has guaranteed. See Note 13 to the Consolidated Financial Statements, " Commitments and Contingencies ," for further discussion of the NEXUS guarantee arrangements.
Changes in Accumulated Other Comprehensive Income (Loss)	Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is the change in common shareholders' equity during a period from transactions and events from non-owner sources, including Net Income. The amounts recorded to Accumulated other comprehensive income (loss) for DTE Energy include changes in benefit obligations, consisting of deferred actuarial losses and prior service costs, unrealized gains and losses from derivatives accounted for as cash flow hedges, DTE Energy's interest in other comprehensive income of equity investees which comprise the net unrealized gains and losses on investments, and foreign currency translation adjustments. DTE Energy releases income tax effects from accumulated other comprehensive income when the circumstances upon which they are premised cease to exist. Changes in Accumulated other comprehensive income (loss) are presented in DTE Energy's Consolidated Statements of Changes in Equity and DTE Electric's Consolidated Statements of Changes in Shareholder's Equity. For further discussion regarding changes in Accumulated other comprehensive income (loss), see Note 3 to the Consolidated Financial Statements, " New Accounting Pronouncements ." For the three and nine months ended September 30, 2019 and 2018 , reclassifications out of Accumulated other comprehensive income (loss) not relating to the adoption of new accounting pronouncements for DTE Energy were not material.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held to satisfy requirements of certain debt and DTE Energy partnership operating agreements. Restricted cash designated for interest and principal payments within one year is classified as a Current Asset.
Intangible Assets	DTE Energy amortizes customer relationship and contract intangible assets on a straight-line basis over the expected period of benefit.
Recently Adopted and Recently Issued Pronouncements	Recently Adopted Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), as amended. This guidance requires a lessee to account for leases as finance or operating leases and disclose key information about leasing arrangements. Both types of leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition, depending on the lease classification. The Registrants adopted the standard on January 1, 2019 using the prospective approach. The standard provides a number of transition practical expedients of which the Registrants elected the package of three expedients that must be taken together, allowing entities to not reassess whether an agreement is a lease, to carryforward the existing lease classification, and to not reassess initial direct costs associated with existing leases; but did not elect to apply hindsight in determining lease term and impairment of the right-of-use assets. The Registrants also elected to not evaluate land easements under the new guidance at adoption if they were not previously accounted for as leases. These practical expedients apply to leases that commenced prior to January 1, 2019. At adoption of the new standard, the Registrants recognized on the Consolidated Statements of Financial Position, right-of-use assets and lease liabilities for certain operating leases of approximately $137 million and $130 million , respectively, for DTE Energy and approximately $74 million and $67 million , respectively, for DTE Electric as of January 1, 2019. The right-of-use lease assets include $9 million of prepaid lease costs that have been reclassified from Other assets, current and noncurrent, and $2 million of deferred lease costs that have been reclassified from Other liabilities, current and noncurrent, for the Registrants. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Statements of Operations but required additional disclosures for leases. See Note 12 to the Consolidated Financial Statements, " Leases ." In February 2018, the FASB issued ASU No. 2018-02, Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings from stranded tax effects resulting from the TCJA. The amendments in this update also require entities to disclose their accounting policy for releasing income tax effects from accumulated other comprehensive income. The Registrants adopted the standard effective January 1, 2019. Upon adoption, DTE Energy reclassified $25 million of income tax effects from Accumulated other comprehensive income (loss) to Retained Earnings. Recently Issued Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as amended. The amendments in this update replace the incurred loss impairment methodology in current generally accepted accounting principles with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasts, to develop credit loss estimates. The ASU requires entities to use the new methodology to measure impairment of financial instruments, including accounts receivable, and may result in earlier recognition of credit losses than under current generally accepted accounting principles. Entities will apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The ASU is effective for the Registrants beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement . The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-14, Compensation — Retirement Benefits — Defined Benefit Plans (Subtopic 715-20): Disclosure Framework — Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans . The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The ASU is effective for the Registrants for fiscal years ending after December 15, 2020. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract . The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The ASU may be applied using either a retrospective or prospective approach. The Registrants are currently evaluating the transition methods and assessing the impact of this standard on their Consolidated Financial Statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities . The amendments in this update modify the requirements for determining whether a decision-making fee is a variable interest and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants anticipate adopting the ASU on its effective date. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.
Fair Value Measurement	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. The Registrants make certain assumptions they believe that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at September 30, 2019 and December 31, 2018 . The Registrants believe they use valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Registrants classify fair value balances based on the fair value hierarchy defined as follows: • Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Registrants have the ability to access as of the reporting date. • Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
Nuclear Decommissioning Trusts and Other Investments	Nuclear Decommissioning Trusts and Other Investments The nuclear decommissioning trusts and other investments hold debt and equity securities directly and indirectly through commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. Commingled funds that hold exchange-traded equity or debt securities are valued based on stated NAVs. Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. Other assets such as private equity investments are classified as NAV assets. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered preferable. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices.
Derivative Assets and Liabilities	Derivative Assets and Liabilities Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options, and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. The Registrants consider the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time, and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality, and basis differential factors. The Registrants monitor the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Registrants have established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy.
Fair Value Transfer	Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period.
Derivatives	The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period. The Registrants' primary market risk exposure is associated with commodity prices, credit, and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil, certain coal forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized. DTE Gas — DTE Gas purchases, stores, transports, distributes, and sells natural gas and sells storage and transportation capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2022. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. DTE Gas may also sell forward transportation and storage capacity contracts. Forward transportation and storage contracts are generally not derivatives and are therefore accounted for under the accrual method. Gas Storage and Pipelines — This segment is primarily engaged in services related to the gathering, transportation, and storage of natural gas. Primarily fixed-priced contracts are used in the marketing and management of transportation and storage services. Generally, these contracts are not derivatives and are therefore accounted for under the accrual method. Power and Industrial Projects — This segment manages and operates energy and pulverized coal projects, a coke battery, reduced emissions fuel projects, renewable gas recovery, and power generation assets. Primarily fixed-price contracts are used in the marketing and management of the segment assets. These contracts are generally not derivatives and are therefore accounted for under the accrual method. Energy Trading — Commodity Price Risk — Energy Trading markets and trades electricity, natural gas physical products, and energy financial instruments, and provides energy and asset management services utilizing energy commodity derivative instruments. Forwards, futures, options, and swap agreements are used to manage exposure to the risk of market price and volume fluctuations in its operations. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Energy Trading — Foreign Currency Exchange Risk — Energy Trading has foreign currency exchange forward contracts to economically hedge fixed Canadian dollar commitments existing under natural gas and power purchase and sale contracts and natural gas transportation contracts. Energy Trading enters into these contracts to mitigate price volatility with respect to fluctuations of the Canadian dollar relative to the U.S. dollar. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Corporate and Other — Interest Rate Risk — DTE Energy may use interest rate swaps, treasury locks, and other derivatives to hedge the risk associated with interest rate market volatility. Credit Risk — DTE Energy maintains credit policies that significantly minimize overall credit risk. These policies include an evaluation of potential customers’ and counterparties’ financial condition, including the viability of underlying productive assets, credit rating, collateral requirements, or other credit enhancements such as letters of credit or guarantees. DTE Energy generally uses standardized agreements that allow the netting of positive and negative transactions associated with a single counterparty. DTE Energy maintains a provision for credit losses based on factors surrounding the credit risk of its customers, historical trends, and other information. Based on DTE Energy's credit policies and its September 30, 2019 provision for credit losses, DTE Energy’s exposure to counterparty nonperformance is not expected to have a material adverse effect on DTE Energy's Consolidated Financial Statements.
Derivatives, Offsetting Fair Value Amounts	Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of $2 million and $4 million outstanding at September 30, 2019 and December 31, 2018 , respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $6 million and $8 million at September 30, 2019 and December 31, 2018 , respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. For contracts with certain clearing agents, the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a Derivative asset or liability or 2) an Account receivable or payable. Other than certain clearing agents, Accounts receivable and Accounts payable that are subject to netting arrangements have not been offset against the fair value of Derivative assets and liabilities.
Derivatives, Methods of Accounting, Derivatives Not Designated or Qualifying as Hedges	Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility.
Income Tax	The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2019
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of September 30, 2019 and December 31, 2018 . All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which DTE Energy holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below. Amounts for DTE Energy's consolidated VIEs are as follows: September 30, 2019 December 31, 2018 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 20 $ 12 $ 32 $ 25 $ 14 $ 39 Restricted cash — — — — 5 5 Accounts receivable 10 27 37 9 37 46 Inventories — 97 97 1 92 93 Property, plant, and equipment, net 406 36 442 395 46 441 Goodwill 25 — 25 25 — 25 Intangible assets 546 — 546 557 — 557 Other current and long-term assets 1 — 1 3 — 3 $ 1,008 $ 172 $ 1,180 $ 1,015 $ 194 $ 1,209 LIABILITIES Accounts payable and accrued current liabilities $ 5 $ 18 $ 23 $ 3 $ 31 $ 34 Other current and long-term liabilities 6 7 13 9 10 19 $ 11 $ 25 $ 36 $ 12 $ 41 $ 53 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at September 30, 2019 and 55% at December 31, 2018.
Summary of Amounts for Non-Consolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs are as follows: September 30, 2019 December 31, 2018 (In millions) Investments in equity method investees $ 1,487 $ 1,425 Notes receivable $ 26 $ 15 Future funding commitments $ 55 $ 55

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of Other Income	The following is a summary of DTE Energy's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Income from REF entities $ 40 $ 27 $ 96 $ 75 Equity earnings of equity method investees 34 46 77 99 Gains from equity securities 3 5 27 6 Contract services 7 11 21 43 Allowance for equity funds used during construction 5 7 18 20 Other 9 3 20 19 $ 98 $ 99 $ 259 $ 262 The following is a summary of DTE Electric's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Gains from equity securities allocated from DTE Energy $ 3 $ 5 $ 27 $ 6 Contract services 7 11 23 44 Allowance for equity funds used during construction 5 5 17 14 Other 5 2 11 8 $ 20 $ 23 $ 78 $ 72
Schedule of Effective Tax Rates	The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 DTE Energy 13 % 9 % 12 % 12 % DTE Electric 16 % 21 % 16 % 22 %
Schedule of Finite-Lived Intangible Assets by Major Class	The Registrants have certain Intangible assets as shown below: September 30, 2019 December 31, 2018 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 779 $ (58 ) $ 721 $ 779 $ (44 ) $ 735 Contract intangibles 6 to 26 years 270 (72 ) 198 159 (66 ) 93 1,049 (130 ) 919 938 (110 ) 828 DTE Electric renewable energy credits (b) 20 — 20 20 — 20 DTE Electric emission allowances (b) 1 — 1 1 — 1 21 — 21 21 — 21 Long-term intangible assets DTE Electric $ 21 $ — $ 21 $ 21 $ — $ 21 DTE Energy $ 1,070 $ (130 ) $ 940 $ 959 $ (110 ) $ 849 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business.
Schedule of Indefinite-Lived Intangible Assets	The Registrants have certain Intangible assets as shown below: September 30, 2019 December 31, 2018 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 779 $ (58 ) $ 721 $ 779 $ (44 ) $ 735 Contract intangibles 6 to 26 years 270 (72 ) 198 159 (66 ) 93 1,049 (130 ) 919 938 (110 ) 828 DTE Electric renewable energy credits (b) 20 — 20 20 — 20 DTE Electric emission allowances (b) 1 — 1 1 — 1 21 — 21 21 — 21 Long-term intangible assets DTE Electric $ 21 $ — $ 21 $ 21 $ — $ 21 DTE Energy $ 1,070 $ (130 ) $ 940 $ 959 $ (110 ) $ 849 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes DTE Energy's estimated customer relationship and contract intangible amortization expense expected to be recognized during each year through 2024: Remaining 2019 2020 2021 2022 2023 2024 (In millions) Estimated amortization expense $ 9 $ 35 $ 34 $ 34 $ 34 $ 34

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Final Purchase Price Allocation	The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 111 Property, plant, and equipment, net 59 Working capital 4 Total $ 174

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Electric (a) Residential $ 791 $ 773 $ 1,839 $ 1,943 Commercial 515 495 1,358 1,370 Industrial 175 173 497 527 Other (b) 39 80 251 162 Total Electric operating revenues (c) $ 1,520 $ 1,521 $ 3,945 $ 4,002 Gas Gas sales $ 87 $ 89 $ 727 $ 726 End User Transportation 35 34 157 168 Intermediate Transportation 15 9 57 38 Other (b) 18 32 102 37 Total Gas operating revenues (d) $ 155 $ 164 $ 1,043 $ 969 Other segment operating revenues Gas Storage and Pipelines (e) $ 126 $ 122 $ 363 $ 363 Power and Industrial Projects (f) $ 406 $ 612 $ 1,196 $ 1,717 Energy Trading (g) $ 1,105 $ 1,332 $ 3,519 $ 3,994 _______________________________________ (a) Revenues under the Electric segment generally represent those of DTE Electric. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $5 million and $6 million of other revenues outside the scope of Topic 606 for the three months ended September 30, 2019 and 2018, respectively , and $14 million and $15 million for the nine months ended September 30, 2019 and 2018 , respectively. (d) Includes $4 million under Alternative Revenue Programs for the nine months ended September 30, 2018 . Also includes $2 million of other revenues for the three months ended September 30, 2019 and 2018 and $6 million for the nine months ended September 30, 2019 and 2018 , which are both outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million and $7 million of contracts accounted for as leases for the three and nine months ended September 30, 2019 , respectively. (f) Includes revenues outside the scope of Topic 606 primarily related to $33 million and $37 million of contracts accounted for as leases for the three months ended September 30, 2019 and 2018, respectively , and $94 million and $93 million for the nine months ended September 30, 2019 and 2018 , respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $791 million and $1.1 billion of derivatives for the three months ended September 30, 2019 and 2018, respectively , and $2.6 billion and $3.2 billion of derivatives for the nine months ended September 30, 2019 and 2018 , respectively.
Summary of Deferred Revenue Activity	The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2019 $ 74 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 41 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (50 ) Ending Balance, September 30, 2019 $ 65
Deferred Revenue Amounts Expected to be Recognized as Revenue in Future Periods	The following table represents deferred revenue amounts for DTE Energy that are expected to be recognized as revenue in future periods: DTE Energy (In millions) 2019 $ 9 2020 25 2021 6 2022 7 2023 6 2024 and thereafter 12 $ 65 The Registrants expect to recognize revenue for the following amounts related to fixed consideration associated with remaining performance obligations in each of the future periods noted: DTE Energy DTE Electric (In millions) 2019 $ 52 $ 3 2020 290 — 2021 269 — 2022 206 — 2023 142 — 2024 and thereafter 648 — $ 1,607 $ 3
Schedule of Expenses Recognized for Estimated Uncollectible Accounts Receivable	The following table represents expenses recognized for estimated uncollectible accounts receivable: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) DTE Energy $ 28 $ 39 $ 81 $ 95 DTE Electric $ 17 $ 26 $ 47 $ 57

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following is a reconciliation of DTE Energy's basic and diluted income per share calculation: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — basic $ 318 $ 333 $ 900 $ 927 Average number of common shares outstanding — basic 183 182 183 181 Basic Earnings per Common Share $ 1.74 $ 1.84 $ 4.93 $ 5.13 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — diluted $ 318 $ 333 $ 900 $ 927 Average number of common shares outstanding — basic 183 182 183 181 Incremental shares attributable to: Average dilutive equity units, performance share awards, and stock options 1 — 1 — Average number of common shares outstanding — diluted 184 182 184 181 Diluted Earnings per Common Share (a) $ 1.73 $ 1.84 $ 4.91 $ 5.13 _______________________________________ (a) The 2016 Equity Units excluded from the calculation of diluted EPS were approximately 6.2 million for the three months ended September 30, 2018 and 6.4 million for the nine months ended September 30, 2018 as the dilutive stock price threshold was not met.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis	The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis (a) : September 30, 2019 December 31, 2018 Level Level Level Other (b) Netting (c) Net Balance Level Level Level Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 21 $ — $ — $ — $ — $ 21 $ 16 $ 2 $ — $ — $ — $ 18 Nuclear decommissioning trusts Equity securities 990 — — — — 990 851 — — — — 851 Fixed income securities 9 535 — — — 544 12 490 — — — 502 Private equity and other — — — 34 — 34 — — — 20 — 20 Cash equivalents 9 — — — — 9 5 — — — — 5 Other investments (e) Equity securities 130 — — — — 130 110 — — — — 110 Fixed income securities 78 — — — — 78 69 — — — — 69 Cash equivalents 4 — — — — 4 4 — — — — 4 Derivative assets Commodity contracts Natural gas 109 90 54 — (189 ) 64 199 87 63 — (277 ) 72 Electricity — 128 36 — (124 ) 40 — 247 56 — (252 ) 51 Other 5 — 5 — (5 ) 5 — — 7 — (1 ) 6 Foreign currency exchange contracts — 2 — — — 2 — 4 — — — 4 Total derivative assets 114 220 95 — (318 ) 111 199 338 126 — (530 ) 133 Total $ 1,355 $ 755 $ 95 $ 34 $ (318 ) $ 1,921 $ 1,266 $ 830 $ 126 $ 20 $ (530 ) $ 1,712 Liabilities Derivative liabilities Commodity contracts Natural gas $ (130 ) $ (72 ) $ (95 ) $ — $ 189 $ (108 ) $ (197 ) $ (71 ) $ (112 ) $ — $ 272 $ (108 ) Electricity — (127 ) (28 ) — 124 (31 ) — (227 ) (58 ) — 240 (45 ) Other (7 ) (1 ) — — 5 (3 ) — (1 ) — — 1 — Interest rate contracts — — — — — — — (3 ) — — — (3 ) Total derivative liabilities (137 ) (200 ) (123 ) — 318 (142 ) (197 ) (302 ) (170 ) — 513 (156 ) Total $ (137 ) $ (200 ) $ (123 ) $ — $ 318 $ (142 ) $ (197 ) $ (302 ) $ (170 ) $ — $ 513 $ (156 ) Net Assets (Liabilities) at end of period $ 1,218 $ 555 $ (28 ) $ 34 $ — $ 1,779 $ 1,069 $ 528 $ (44 ) $ 20 $ (17 ) $ 1,556 Assets Current $ 130 $ 175 $ 62 $ — $ (271 ) $ 96 $ 212 $ 273 $ 96 $ — $ (461 ) $ 120 Noncurrent 1,225 580 33 34 (47 ) 1,825 1,054 557 30 20 (69 ) 1,592 Total Assets $ 1,355 $ 755 $ 95 $ 34 $ (318 ) $ 1,921 $ 1,266 $ 830 $ 126 $ 20 $ (530 ) $ 1,712 Liabilities Current $ (123 ) $ (163 ) $ (53 ) $ — $ 271 $ (68 ) $ (191 ) $ (251 ) $ (76 ) $ — $ 451 $ (67 ) Noncurrent (14 ) (37 ) (70 ) — 47 (74 ) (6 ) (51 ) (94 ) — 62 (89 ) Total Liabilities $ (137 ) $ (200 ) $ (123 ) $ — $ 318 $ (142 ) $ (197 ) $ (302 ) $ (170 ) $ — $ 513 $ (156 ) Net Assets (Liabilities) at end of period $ 1,218 $ 555 $ (28 ) $ 34 $ — $ 1,779 $ 1,069 $ 528 $ (44 ) $ 20 $ (17 ) $ 1,556 _______________________________________ (a) See footnotes on following page. _______________________________________ (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties. (d) At September 30, 2019 , the $21 million consisted of $10 million and $11 million of cash equivalents included in Cash and cash equivalents and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2018 , the $18 million consisted of $3 million , $5 million and $10 million of cash equivalents included in Cash and cash equivalents, Restricted cash, and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. (e) Excludes cash surrender value of life insurance investments. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of: September 30, 2019 December 31, 2018 Level 1 Level 2 Level 3 Other (a) Net Balance Level 1 Level 2 Level 3 Other (a) Net Balance (In millions) Assets Cash equivalents (b) $ 11 $ — $ — $ — $ 11 $ 8 $ 2 $ — $ — $ 10 Nuclear decommissioning trusts Equity securities 990 — — — 990 851 — — — 851 Fixed income securities 9 535 — — 544 12 490 — — 502 Private equity and other — — — 34 34 — — — 20 20 Cash equivalents 9 — — — 9 5 — — — 5 Other investments Equity securities 12 — — — 12 10 — — — 10 Derivative assets — FTRs — — 5 — 5 — — 6 — 6 Total $ 1,031 $ 535 $ 5 $ 34 $ 1,605 $ 886 $ 492 $ 6 $ 20 $ 1,404 Assets Current $ 11 $ — $ 5 $ — $ 16 $ 8 $ 2 $ 6 $ — $ 16 Noncurrent 1,020 535 — 34 1,589 878 490 — 20 1,388 Total Assets $ 1,031 $ 535 $ 5 $ 34 $ 1,605 $ 886 $ 492 $ 6 $ 20 $ 1,404 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At September 30, 2019 , the $11 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2018 , the $10 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position.
Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of June 30 $ (10 ) $ 10 $ 9 $ 9 $ (25 ) $ (13 ) $ 15 $ (23 ) Transfers into Level 3 from Level 2 — — — — — — — — Transfers from Level 3 into Level 2 — — — — — — — — Total gains (losses) Included in earnings (35 ) 37 — 2 (30 ) 21 — (9 ) Recorded in Regulatory liabilities — — (3 ) (3 ) — — (8 ) (8 ) Purchases, issuances, and settlements Settlements 4 (39 ) (1 ) (36 ) 9 (18 ) (1 ) (10 ) Net Assets (Liabilities) as of September 30 $ (41 ) $ 8 $ 5 $ (28 ) $ (46 ) $ (10 ) $ 6 $ (50 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (36 ) $ 15 $ (1 ) $ (22 ) $ (31 ) $ 10 $ (1 ) $ (22 ) Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (49 ) $ (2 ) $ 7 $ (44 ) $ (29 ) $ 12 $ 8 $ (9 ) Transfers into Level 3 from Level 2 — — — — — — — — Transfers from Level 3 into Level 2 — — — — (3 ) — — (3 ) Total gains (losses) Included in earnings (4 ) 47 (1 ) 42 (128 ) 25 1 (102 ) Recorded in Regulatory liabilities — — 3 3 — — 6 6 Purchases, issuances, and settlements Settlements 12 (37 ) (4 ) (29 ) 114 (47 ) (9 ) 58 Net Assets (Liabilities) as of September 30 $ (41 ) $ 8 $ 5 $ (28 ) $ (46 ) $ (10 ) $ 6 $ (50 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (20 ) $ 32 $ (6 ) $ 6 $ (109 ) $ 4 $ (3 ) $ (108 ) The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Net Assets as of beginning of period $ 9 $ 15 $ 6 $ 9 Change in fair value recorded in Regulatory liabilities (3 ) (8 ) 3 6 Purchases, issuances, and settlements Settlements (1 ) (1 ) (4 ) (9 ) Net Assets as of September 30 $ 5 $ 6 $ 5 $ 6 The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2019 and 2018 and reflected in DTE Electric's Consolidated Statements of Financial Position $ (1 ) $ (2 ) $ 5 $ 6
Unobservable Inputs Related to Level 3 Assets and Liabilities	The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities: September 30, 2019 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 54 $ (95 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.55 ) — $ 6.17 /MMBtu $ (0.09 )/MMBtu Electricity $ 36 $ (28 ) Discounted Cash Flow Forward basis price (per MWh) $ (13 ) — $ 7 /MWh $ — December 31, 2018 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 63 $ (112 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (2.15 ) — $ 5.59 /MMBtu $ (0.10 )/MMBtu Electricity $ 56 $ (58 ) Discounted Cash Flow Forward basis price (per MWh) $ (7 ) — $ 9 /MWh $ 1 /MWh
Carrying Amount of Fair Value of Financial Instruments	The following table presents the carrying amount and fair value of financial instruments for DTE Energy: September 30, 2019 December 31, 2018 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) , excluding lessor finance leases $ 178 $ — $ — $ 178 $ 40 $ — $ — $ 40 Dividends payable $ 173 $ 173 $ — $ — $ 172 $ 172 $ — $ — Short-term borrowings $ 724 $ — $ 724 $ — $ 609 $ — $ 609 $ — Notes payable — Other (b) , excluding lessee finance leases $ 27 $ — $ — $ 27 $ 41 $ — $ — $ 41 Long-term debt (c) $ 15,056 $ 1,277 $ 14,216 $ 1,138 $ 13,622 $ 1,796 $ 10,712 $ 1,317 _______________________________________ (a) Current portion included in Current Assets — Other on DTE Energy's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Energy's Consolidated Statements of Financial Position. (c) Includes debt due within one year , unamortized debt discounts, and issuance costs. Excludes finance lease obligations. The following table presents the carrying amount and fair value of financial instruments for DTE Electric: September 30, 2019 December 31, 2018 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable — Other (a) , excluding lessor finance leases $ 14 $ — $ — $ 14 $ 6 $ — $ — $ 6 Short-term borrowings — affiliates $ 97 $ — $ — $ 97 $ 101 $ — $ — $ 101 Short-term borrowings — other $ 382 $ — $ 382 $ — $ 149 $ — $ 149 $ — Notes payable — Other (b) , excluding lessee finance leases $ 23 $ — $ — $ 23 $ 21 $ — $ — $ 21 Long-term debt (c) $ 7,179 $ — $ 7,996 $ 176 $ 6,538 $ — $ 6,552 $ 161 _______________________________________ (a) Included in Current Assets — Other on DTE Electric's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Electric's Consolidated Statements of Financial Position. (c) Includes debt due within one year , unamortized debt discounts, and issuance costs. Excludes finance lease obligations.
Fair Value of Nuclear Decommissioning Trust Fund Assets	The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: September 30, 2019 December 31, 2018 (In millions) Fermi 2 $ 1,567 $ 1,372 Fermi 1 3 3 Low-level radioactive waste 7 3 $ 1,577 $ 1,378
Schedule of Realized Gains and Losses and Proceeds from Sale of Securities by Nuclear Decommissioning Trust Funds	The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Realized gains $ 15 $ 10 $ 43 $ 52 Realized losses $ (8 ) $ (7 ) $ (25 ) $ (22 ) Proceeds from sale of securities $ 198 $ 194 $ 594 $ 810
Fair Value and Unrealized Gains and Losses for Nuclear Decommissioning Trust Funds	The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds: September 30, 2019 December 31, 2018 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 990 $ 335 $ (53 ) $ 851 $ 235 $ (79 ) Fixed income securities 544 27 (1 ) 502 7 (8 ) Private equity and other 34 — — 20 — — Cash equivalents 9 — — 5 — — $ 1,577 $ 362 $ (54 ) $ 1,378 $ 242 $ (87 )
Fair Value of the Fixed Income Securities Held in Nuclear Decommissioning Trust Funds	The following table summarizes the fair value of the fixed income securities held in nuclear decommissioning trust funds by contractual maturity: September 30, 2019 (In millions) Due within one year $ 23 Due after one through five years 98 Due after five through ten years 108 Due after ten years 315 $ 544

Financial and Other Derivativ_2

Financial and Other Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	The following table presents the fair value of derivative instruments for DTE Energy: September 30, 2019 December 31, 2018 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Interest rate contracts $ — $ — $ — $ (3 ) Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 253 $ (297 ) $ 349 $ (380 ) Electricity 164 (155 ) 303 (285 ) Other 10 (8 ) 7 (1 ) Foreign currency exchange contracts 2 — 4 — Total derivatives not designated as hedging instruments $ 429 $ (460 ) $ 663 $ (666 ) Current $ 346 $ (339 ) $ 563 $ (518 ) Noncurrent 83 (121 ) 100 (151 ) Total derivatives $ 429 $ (460 ) $ 663 $ (669 ) The following table presents the fair value of derivative instruments for DTE Electric: September 30, 2019 December 31, 2018 (In millions) FTRs — Other current assets $ 5 $ 6 Total derivatives not designated as hedging instruments $ 5 $ 6
Netting Offsets of Derivative Assets	The following table presents net cash collateral offsetting arrangements for DTE Energy: September 30, 2019 December 31, 2018 (In millions) Cash collateral netted against Derivative assets $ — $ (17 ) Cash collateral recorded in Accounts receivable (a) 9 10 Cash collateral recorded in Accounts payable (a) (6 ) (6 ) Total net cash collateral posted (received) $ 3 $ (13 ) _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 2019 December 31, 2018 Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position (In millions) Derivative assets Commodity contracts Natural gas $ 253 $ (189 ) $ 64 $ 349 $ (277 ) $ 72 Electricity 164 (124 ) 40 303 (252 ) 51 Other 10 (5 ) 5 7 (1 ) 6 Foreign currency exchange contracts 2 — 2 4 — 4 Total derivative assets $ 429 $ (318 ) $ 111 $ 663 $ (530 ) $ 133 Derivative liabilities Commodity contracts Natural gas $ (297 ) $ 189 $ (108 ) $ (380 ) $ 272 $ (108 ) Electricity (155 ) 124 (31 ) (285 ) 240 (45 ) Other (8 ) 5 (3 ) (1 ) 1 — Interest rate contracts — — — (3 ) — (3 ) Total derivative liabilities $ (460 ) $ 318 $ (142 ) $ (669 ) $ 513 $ (156 )
Netting Offsets of Derivative Liabilities	The following table presents net cash collateral offsetting arrangements for DTE Energy: September 30, 2019 December 31, 2018 (In millions) Cash collateral netted against Derivative assets $ — $ (17 ) Cash collateral recorded in Accounts receivable (a) 9 10 Cash collateral recorded in Accounts payable (a) (6 ) (6 ) Total net cash collateral posted (received) $ 3 $ (13 ) _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 2019 December 31, 2018 Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position (In millions) Derivative assets Commodity contracts Natural gas $ 253 $ (189 ) $ 64 $ 349 $ (277 ) $ 72 Electricity 164 (124 ) 40 303 (252 ) 51 Other 10 (5 ) 5 7 (1 ) 6 Foreign currency exchange contracts 2 — 2 4 — 4 Total derivative assets $ 429 $ (318 ) $ 111 $ 663 $ (530 ) $ 133 Derivative liabilities Commodity contracts Natural gas $ (297 ) $ 189 $ (108 ) $ (380 ) $ 272 $ (108 ) Electricity (155 ) 124 (31 ) (285 ) 240 (45 ) Other (8 ) 5 (3 ) (1 ) 1 — Interest rate contracts — — — (3 ) — (3 ) Total derivative liabilities $ (460 ) $ 318 $ (142 ) $ (669 ) $ 513 $ (156 )
Netting Offsets of Derivative Assets and Liabilities Reconciliation to the Statements of Financial Position	The following table presents the netting offsets of Derivative assets and liabilities showing the reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position: September 30, 2019 December 31, 2018 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 346 $ 83 $ (339 ) $ (121 ) $ 563 $ 100 $ (518 ) $ (151 ) Counterparty netting (271 ) (47 ) 271 47 (451 ) (62 ) 451 62 Collateral adjustment — — — — (10 ) (7 ) — — Total derivatives as reported $ 75 $ 36 $ (68 ) $ (74 ) $ 102 $ 31 $ (67 ) $ (89 )
Gain (Loss) Recognized in Income on Derivatives	The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations is as follows: Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended September 30, Gain (Loss) Recognized in Income on Derivatives for the Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (5 ) $ (29 ) $ 4 $ (51 ) Natural gas Fuel, purchased power, and gas — non-utility (47 ) (6 ) (7 ) (74 ) Electricity Operating Revenues — Non-utility operations 54 26 21 37 Other Operating Revenues — Non-utility operations (11 ) — (11 ) 1 Foreign currency exchange contracts Operating Revenues — Non-utility operations 1 (2 ) (2 ) 2 Total $ (8 ) $ (11 ) $ 5 $ (85 )
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of September 30, 2019 : Commodity Number of Units Natural gas (MMBtu) 2,018,659,087 Electricity (MWh) 30,880,332 Foreign currency exchange (CAD) 79,292,076

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Issued Debt	In 2019 , the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric February Mortgage Bonds (a) 3.95% 2049 $ 650 DTE Energy June Senior Notes (b) 2.60% 2022 300 DTE Energy June Senior Notes (b) 3.40% 2029 500 $ 1,450 _______________________________________ (a) Bonds were issued as Green Bonds and the proceeds will be used to finance expenditures for solar and wind energy, payments under power purchase agreements for solar and wind energy, and energy optimization programs. (b) Proceeds were used for the repayment of short-term borrowings and general corporate purposes.

Short-Term Credit Arrangement_2

Short-Term Credit Arrangements and Borrowings (Tables)	9 Months Ended
	Sep. 30, 2019
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under the facilities in place at September 30, 2019 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2021 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 1,760 500 300 2,560 Amounts outstanding at September 30, 2019 Commercial paper issuances 110 382 232 724 Letters of credit 191 — — 191 301 382 232 915 Net availability at September 30, 2019 $ 1,459 $ 118 $ 68 $ 1,645

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Components of Lease Cost and Other Information Related to Leases	The components of lease cost for DTE Energy were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 10 $ 31 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost 2 8 Short-term lease cost 2 7 $ 14 $ 49 The components of lease cost for DTE Electric were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Operating lease cost $ 5 $ 13 Finance lease cost: Amortization of right-of-use assets — 3 Interest of lease liabilities — — Total finance lease cost — 3 Variable lease cost — — Short-term lease cost 1 2 $ 6 $ 18 Other information related to leases were as follows: DTE Energy DTE Electric Nine Months Ended September 30, 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows from finance leases $ 4 $ 4 Operating cash flows from operating leases $ 30 $ 11 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 37 $ 2 Weighted Average Remaining Lease Term Operating leases 9.7 years 10.6 years Finance leases 2.3 years 2.3 years Weighted Average Discount Rate Operating leases 3.7% 3.7% Finance leases 3.1% 3.1%
Schedule of Maturities of Operating Leases	The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8
Schedule of Maturities of Finance Leases	The Registrants' future minimum lease payments under leases for remaining periods as of September 30, 2019 were as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2019 $ 10 $ 1 $ 4 $ 1 2020 35 4 13 4 2021 26 3 11 3 2022 19 — 7 — 2023 16 — 6 — 2024 and thereafter 62 — 30 — Total future minimum lease payments 168 8 71 8 Imputed interest (30 ) — (13 ) — $ 138 $ 8 $ 58 $ 8
Schedule of Finance Leases Reported on Consolidated Statement of Financial Position	Finance leases reported on the Consolidated Statement of Financial Position were as follows: DTE Energy DTE Electric September 30, 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 8 $ 8 Current lease liabilities, within Current Liabilities — Other $ 3 $ 3
Schedule of Future Minimum Lease Payments and Rental Revenues for Operating Leases	DTE Energy’s minimum future rental revenues under non-cancelable operating leases as of December 31, 2018 were: DTE Energy (In millions) 2019 $ 66 2020 66 2021 64 2022 20 2023 20 2024 and thereafter 196 $ 432 The Registrants' future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows: DTE Energy DTE Electric (In millions) 2019 $ 42 $ 17 2020 30 12 2021 18 10 2022 11 7 2023 8 5 2024 and thereafter 45 29 $ 154 $ 80
Schedule of Lease Income Associated with Operating Leases	DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 (In millions) Fixed payments $ 17 $ 51 Variable payments 40 92 $ 57 $ 143
Schedule of Minimum Future Rental Revenues under Operating Leases	DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of September 30, 2019 were: DTE Energy (In millions) 2019 $ 16 2020 66 2021 64 2022 22 2023 22 2024 and thereafter 216 $ 406
Schedule of Property under Operating Leases - Topic 842	Property under operating leases for DTE Energy was as follows: DTE Energy September 30, 2019 (In millions) Gross property under operating leases $ 444 Accumulated amortization of property under operating leases $ 166
Components of Net Investment in Finance Leases	The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2019 (In millions) 2019 $ 3 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 13 Residual value of leased pipeline 40 Less unearned income 6 Net investment in finance lease 47 Less current portion 5 $ 42
Components of Net Investment in Capital Leases	The components of DTE Energy’s net investment in capital leases at December 31, 2018 were as follows: DTE Energy (In millions) 2019 $ 10 2020 9 2021 — 2022 — 2023 — 2024 and thereafter 1 Total minimum future lease receipts 20 Residual value of leased pipeline 40 Less unearned income 9 Net investment in capital lease 51 Less current portion 5 $ 46
Schedule of Property under Operating Leases - Topic 840	Property under operating leases for DTE Energy as of December 31, 2018 were as follows: DTE Energy (In millions) Gross property under operating leases $ 447 Accumulated amortization of property under operating leases $ 148

Retirement Benefits and Trust_2

Retirement Benefits and Trusteed Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Defined Benefit Plan [Abstract]
Schedule of Net Periodic Benefit Costs (Credits)	The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Other Postretirement Benefits Three Months Ended September 30, 2019 2018 (In millions) Service cost $ 4 $ 5 Interest cost 13 13 Expected return on plan assets (21 ) (25 ) Amortization of: Net actuarial loss 1 3 Prior service credit (1 ) — Net periodic benefit credit $ (4 ) $ (4 ) Other Postretirement Benefits Nine Months Ended September 30, 2019 2018 (In millions) Service cost $ 12 $ 15 Interest cost 40 40 Expected return on plan assets (63 ) (74 ) Amortization of: Net actuarial loss 3 7 Prior service credit (5 ) — Net periodic benefit credit $ (13 ) $ (12 ) The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended September 30, 2019 2018 2019 2018 (In millions) Service cost $ 21 $ 24 $ 5 $ 6 Interest cost 55 51 18 18 Expected return on plan assets (82 ) (82 ) (30 ) (36 ) Amortization of: Net actuarial loss 33 43 3 3 Prior service credit — — (3 ) — Net periodic benefit cost (credit) $ 27 $ 36 $ (7 ) $ (9 ) Pension Benefits Other Postretirement Benefits Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Service cost $ 63 $ 74 $ 16 $ 20 Interest cost 164 151 53 52 Expected return on plan assets (244 ) (247 ) (92 ) (107 ) Amortization of: Net actuarial loss 99 132 9 8 Prior service credit — — (7 ) — Net periodic benefit cost (credit) $ 82 $ 110 $ (21 ) $ (27 )
Schedule of Defined Benefit Plans Disclosures	During 2019 , DTE Energy contributed the following amounts of DTE Energy common stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust: Date Number of Shares Price per Share Amount (In millions) March 5, 2019 814,597 $ 122.76 $ 100

Segment and Related Informati_2

Segment and Related Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Electric $ 16 $ 13 $ 43 $ 39 Gas 3 3 8 9 Gas Storage and Pipelines 11 7 17 29 Power and Industrial Projects 160 171 462 488 Energy Trading 4 6 16 18 Corporate and Other 1 1 2 2 $ 195 $ 201 $ 548 $ 585 Financial data of DTE Energy's business segments follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Operating Revenues — Utility operations Electric $ 1,520 $ 1,521 $ 3,945 $ 4,002 Gas 155 164 1,043 969 Operating Revenues — Non-utility operations Gas Storage and Pipelines 126 122 363 363 Power and Industrial Projects 406 612 1,196 1,717 Energy Trading 1,105 1,332 3,519 3,994 Corporate and Other 2 — 3 2 Reconciliation and Eliminations (195 ) (201 ) (548 ) (585 ) Total $ 3,119 $ 3,550 $ 9,521 $ 10,462 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 307 $ 305 $ 587 $ 608 Gas (38 ) (30 ) 121 88 Gas Storage and Pipelines 60 66 158 188 Power and Industrial Projects 49 58 104 146 Energy Trading (14 ) (13 ) 12 13 Corporate and Other (45 ) (52 ) (80 ) (114 ) Net Income Attributable to DTE Energy Company $ 319 $ 334 $ 902 $ 929

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details Textuals) customer in Millions	Sep. 30, 2019USD ($)customer
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of electric utility customers | customer	2.2
Number of gas utility customers | customer	1.3
Significant potential exposure | $	$ 0
DTE Electric
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Significant potential exposure | $	$ 0
NEXUS pipeline
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Ownership interest	50.00%
SGG | Midstream Natural Gas Assets
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Percent of assets acquired	85.00%

Organization and Basis of Pre_4

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	5 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 76	$ 76	$ 71
Restricted cash	0	0	5
Accounts receivable	1,453	1,453	1,789
Property, plant, and equipment, net	23,758	23,758	21,650
Goodwill	2,293	2,293	2,293
Intangible assets	919	919	828
Total Assets	38,345	38,345	36,288
Variable interest entity, primary beneficiary, restricted
ASSETS
Cash and cash equivalents	32	32	39
Restricted cash	0	0	5
Accounts receivable	37	37	46
Inventories	97	97	93
Property, plant, and equipment, net	442	442	441
Goodwill	25	25	25
Intangible assets	546	546	557
Other current and long-term assets	1	1	3
Total Assets	1,180	1,180	1,209
LIABILITIES
Accounts payable and accrued current liabilities	23	23	34
Other current and long-term liabilities	13	13	19
Total liabilities	36	36	53
SGG
ASSETS
Cash and cash equivalents	20	20	25
Restricted cash	0	0	0
Accounts receivable	10	10	9
Inventories	0	0	1
Property, plant, and equipment, net	406	406	395
Goodwill	25	25	25
Intangible assets	546	546	557
Other current and long-term assets	1	1	3
Total Assets	1,008	1,008	1,015
LIABILITIES
Accounts payable and accrued current liabilities	5	5	3
Other current and long-term liabilities	6	6	9
Total liabilities	$ 11	$ 11	$ 12
VIE ownership and non-ownership percentage		100.00%
VIE ownership percentage	85.00%		55.00%
Other
ASSETS
Cash and cash equivalents	$ 12	$ 12	$ 14
Restricted cash	0	0	5
Accounts receivable	27	27	37
Inventories	97	97	92
Property, plant, and equipment, net	36	36	46
Goodwill	0	0	0
Intangible assets	0	0	0
Other current and long-term assets	0	0	0
Total Assets	172	172	194
LIABILITIES
Accounts payable and accrued current liabilities	18	18	31
Other current and long-term liabilities	7	7	10
Total liabilities	$ 25	$ 25	$ 41

Organization and Basis of Pre_5

Organization and Basis of Presentation (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Investments in equity method investees	$ 1,839	$ 1,771
Notes receivable	193	64
Variable interest entity, non-consolidated
Variable Interest Entity [Line Items]
Investments in equity method investees	1,487	1,425
Notes receivable	26	15
Future funding commitments	$ 55	$ 55

Significant Accounting Polici_4

Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Schedule of Other Nonoperating Income, by Component [Line Items]
Income from REF entities	$ 40	$ 27	$ 96	$ 75
Equity earnings of equity method investees	34	46	77	99
Gains from equity securities	3	5	27	6
Contract services	7	11	21	43
Allowance for equity funds used during construction	5	7	18	20
Other	9	3	20	19
Total other income	98	99	259	262
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Gains from equity securities	3	5	27	6
Contract services	7	11	23	44
Allowance for equity funds used during construction	5	5	17	14
Other	5	2	11	8
Total other income	$ 20	$ 23	$ 78	$ 72

Significant Accounting Polici_5

Significant Accounting Policies (Details Textuals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Effective tax rate increase (decrease)	4.00%		0.00%
Valuation allowance for AMT credit carryover					$ 20
Remeasurement of deferred taxes					21
Unrecognized tax benefits	$ 8		$ 8
Unrecognized compensation cost	88		$ 88
Recognition period (in years)			1 year 3 months 18 days
Amortization of intangible assets	$ 7	$ 7	$ 21	$ 20
DTE Electric
Significant Accounting Policies [Line Items]
Effective tax rate increase (decrease)	(5.00%)		(6.00%)
Remeasurement of deferred taxes					7
Amortization of TCJA regulatory liability			4.00%
Annual production tax credits			1.00%
Measurement period adjustment, decrease to effective tax rate			0.01
Unrecognized tax benefits	$ 10		$ 10
DTE Electric | DTE Energy
Significant Accounting Policies [Line Items]
Income tax payable	13		13
Income tax receivable					$ 8
Allocated costs	$ 9	$ 11	$ 33	$ 27

Significant Accounting Polici_6

Significant Accounting Policies (Income Taxes) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Schedule of Income Taxes [Line Items]
Effective Tax Rate	13.00%	9.00%	12.00%	12.00%
DTE Electric
Schedule of Income Taxes [Line Items]
Effective Tax Rate	16.00%	21.00%	16.00%	22.00%

Significant Accounting Polici_7

Significant Accounting Policies (Intangible Assets) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	$ 1,049	$ 938
Accumulated Amortization	(130)	(110)
Finite-lived intangible assets, net carrying value	919	828
Intangible assets, gross carrying value	1,070	959
Intangible assets, net carrying value	940	849
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	21	21
DTE Electric
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	0	0
Intangible assets, gross carrying value	21	21
Intangible assets, net carrying value	21	21
DTE Electric renewable energy credits | DTE Electric
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	20	20
DTE Electric emission allowances | DTE Electric
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	1	1
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	779	779
Accumulated Amortization	(58)	(44)
Finite-lived intangible assets, net carrying value	721	735
Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	270	159
Accumulated Amortization	(72)	(66)
Finite-lived intangible assets, net carrying value	$ 198	$ 93
Minimum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful Lives	25 years
Minimum | Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Useful Lives	6 years
Maximum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful Lives	40 years
Maximum | Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Useful Lives	26 years

Significant Accounting Polici_8

Significant Accounting Policies (Future Amortization Expense Intangible Assets) (Details) $ in Millions	Sep. 30, 2019USD ($)
Estimated amortization expense
Remaining 2019	$ 9
2020	35
2021	34
2022	34
2023	34
2024	$ 34

New Accounting Pronouncements (

New Accounting Pronouncements (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases	$ 145
Lease liabilities for certain operating leases	138
Reclassification of income tax effects		$ 0	$ 0
DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases	64
Lease liabilities for certain operating leases	$ 58
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		(25)	(5)
Accumulated Other Comprehensive Income (Loss) | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects			(3)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		25	5
Retained Earnings | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects			$ 3
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases		137
Lease liabilities for certain operating leases		130
Prepaid lease costs reclassified from Other assets, current and noncurrent		9
Deferred lease costs reclassified from Other liabilities, current and noncurrent		2
Accounting Standards Update 2016-02 | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases		74
Lease liabilities for certain operating leases		67
Accounting Standards Update 2018-02 | Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		(25)
Accounting Standards Update 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		$ 25

Acquisitions (Details Textuals)

Acquisitions (Details Textuals) $ in Millions	Sep. 20, 2019USD ($)	Sep. 12, 2019USD ($)MW	Jan. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)
Business Acquisition [Line Items]
Consideration paid for entity acquired, paid in cash				$ 174	$ 0
Electric | Heritage Sustainable Energy, Renewable Energy Project
Business Acquisition [Line Items]
Amount of power associated with purchase of renewable energy project | MW		89
Consideration paid for entity acquired, paid in cash		$ 174
Electric | Heritage Sustainable Energy, Renewable Energy Project | Minimum
Business Acquisition [Line Items]
Customer relationship intangible assets, amortization period		11 years
Electric | Heritage Sustainable Energy, Renewable Energy Project | Maximum
Business Acquisition [Line Items]
Customer relationship intangible assets, amortization period		14 years
Electric | Heritage Sustainable Energy, Additional Renewable Energy Project | Forecast
Business Acquisition [Line Items]
Total consideration paid for acquired entity			$ 30
Gas Storage and Pipelines | Generation Pipeline, LLC
Business Acquisition [Line Items]
Portion of consideration paid attributable to DTE Energy	50.00%
Gas Storage and Pipelines | Generation Pipeline, LLC | NEXUS
Business Acquisition [Line Items]
Total consideration paid for acquired entity	$ 163

Acquisitions (Purchase Price Al

Acquisitions (Purchase Price Allocation) (Details) - Electric - Heritage Sustainable Energy, Renewable Energy Project $ in Millions	Sep. 12, 2019USD ($)
Business Acquisition [Line Items]
Contract intangibles	$ 111
Property, plant, and equipment, net	59
Working capital	4
Total	$ 174

Revenue (Disaggregation of Rev

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 3,119	$ 3,550	$ 9,521	$ 10,462
Electric
Disaggregation of Revenue [Line Items]
Revenues	1,520	1,521	3,945	4,002
Electric | Other
Disaggregation of Revenue [Line Items]
Revenues	5	6	14	15
Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues	791	773	1,839	1,943
Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues	515	495	1,358	1,370
Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues	175	173	497	527
Electric | Other
Disaggregation of Revenue [Line Items]
Revenues	39	80	251	162
Gas
Disaggregation of Revenue [Line Items]
Revenues	155	164	1,043	969
Gas | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Revenues				4
Gas | Other
Disaggregation of Revenue [Line Items]
Revenues	2	2	6	6
Gas | Other
Disaggregation of Revenue [Line Items]
Revenues	18	32	102	37
Gas | Gas sales
Disaggregation of Revenue [Line Items]
Revenues	87	89	727	726
Gas | End User Transportation
Disaggregation of Revenue [Line Items]
Revenues	35	34	157	168
Gas | Intermediate Transportation
Disaggregation of Revenue [Line Items]
Revenues	15	9	57	38
Gas Storage and Pipelines
Disaggregation of Revenue [Line Items]
Revenues	126	122	363	363
Lease revenue outside scope of Topic 606	2		7
Power and Industrial Projects
Disaggregation of Revenue [Line Items]
Revenues	406	612	1,196	1,717
Lease revenue outside scope of Topic 606	33	37	94	93
Energy Trading
Disaggregation of Revenue [Line Items]
Revenues	1,105	1,332	3,519	3,994
Gain (loss) on derivative outside scope of Topic 606	$ 791	$ 1,100	$ 2,600	$ 3,200

Revenue (Deferred Revenue) (De

Revenue (Deferred Revenue) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Contract Liability [Roll Forward]
Beginning Balance	$ 74
Increases due to cash received or receivable, excluding amounts recognized as revenue during the period	41
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(50)
Ending Balance	$ 65

Revenue (Expected Recognition

Revenue (Expected Recognition of Deferred Revenue) (Details) $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 9
Remaining performance obligation, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 25
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 12
Remaining performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 65

Revenue (Expected Timing of Pe

Revenue (Expected Timing of Performance Obligation Satisfaction) (Details) $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 9
Remaining performance obligation, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 25
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 12
Remaining performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 65
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 52
Remaining performance obligation, expected timing of satisfaction	3 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	3 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 290
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 269
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 206
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 142
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 648
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,607
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3

Revenue (Expenses Recognized f

Revenue (Expenses Recognized for Estimated Uncollectible Accounts Receivable) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue from External Customer [Line Items]
Allowance for doubtful accounts receivable write-offs	$ 28	$ 39	$ 81	$ 95
DTE Electric
Revenue from External Customer [Line Items]
Allowance for doubtful accounts receivable write-offs	$ 17	$ 26	$ 47	$ 57

Regulatory Matters (Details Tex

Regulatory Matters (Details Textuals) - USD ($) $ in Millions	Aug. 20, 2019	Jul. 08, 2019	May 02, 2019	Feb. 01, 2019	Dec. 06, 2018	Dec. 05, 2018	Nov. 16, 2018	Jul. 06, 2018
DTE Electric | MPSC | Electric Rate Case Filing 2018
Public Utilities, General Disclosures [Line Items]
Requested rate increase				$ 248.6				$ 328
Return on equity percent			10.00%					10.00%
Return on equity requested percent								10.50%
Approved rate increase			$ 125
DTE Electric | MPSC | Electric Rate Case Filing 2019
Public Utilities, General Disclosures [Line Items]
Requested rate increase		$ 351
Return on equity percent		10.00%
Return on equity requested percent		10.50%
DTE Electric | MPSC | 2016 DTE Electric Depreciation Case Filing
Public Utilities, General Disclosures [Line Items]
Approved composite depreciation rate increase					3.72%	3.06%
DTE Gas
Public Utilities, General Disclosures [Line Items]
Calculation C, reduction of annual revenue requirement, requested							$ 12
Calculation C, reduction of annual revenue requirement, approved	$ 13

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 319	$ 334	$ 902	$ 929
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — basic	$ 318	$ 333	$ 900	$ 927
Average number of common shares outstanding — basic (in shares)	183	182	183	181
Basic Earnings per Common Share (in dollars per share)	$ 1.74	$ 1.84	$ 4.93	$ 5.13
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 319	$ 334	$ 902	$ 929
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — diluted	$ 318	$ 333	$ 900	$ 927
Average number of common shares outstanding — basic (in shares)	183	182	183	181
Incremental shares attributable to:
Average dilutive equity units, performance share awards, and stock options (in shares)	1	0	1	0
Average number of common shares outstanding — diluted (in shares)	184	182	184	181
Diluted Earnings per Common Share (in dollars per share)	$ 1.73	$ 1.84	$ 4.91	$ 5.13
Antidilutive securities excluded from computation of earnings per share (in shares)		6.2		6.4

Earnings Per Share (Details Tex

Earnings Per Share (Details Textuals) - USD ($) shares in Thousands, $ in Millions	Oct. 01, 2019	Sep. 30, 2019	Sep. 30, 2018
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Proceeds from issuance of common stock under stock purchase contract associated with 2016 Series C Equity Units		$ 0	$ 7
Subsequent event | Stock Purchase Contract, 2016 Series C Equity Units Subject to Mandatory Redemption
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Shares of common stock issued under stock purchase contracts (in shares)	5,870
Proceeds from issuance of common stock under stock purchase contract associated with 2016 Series C Equity Units	$ 675

Fair Value (Assets and Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative assets
Derivative assets, gross	$ 429	$ 663
Derivative asset, netting	(318)	(530)
Derivative assets, net	111	133
Derivative liabilities
Derivative liabilities, gross	(460)	(669)
Derivative liability, netting	318	513
Derivative liabilities, net	(142)	(156)
Current liabilities
Derivative liabilities
Derivative liabilities, gross	(339)	(518)
Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(121)	(151)
Natural gas
Derivative assets
Derivative assets, gross	253	349
Derivative asset, netting	(189)	(277)
Derivative assets, net	64	72
Derivative liabilities
Derivative liabilities, gross	(297)	(380)
Derivative liability, netting	189	272
Derivative liabilities, net	(108)	(108)
Electricity
Derivative assets
Derivative assets, gross	164	303
Derivative asset, netting	(124)	(252)
Derivative assets, net	40	51
Derivative liabilities
Derivative liabilities, gross	(155)	(285)
Derivative liability, netting	124	240
Derivative liabilities, net	(31)	(45)
Other
Derivative assets
Derivative assets, gross	10	7
Derivative asset, netting	(5)	(1)
Derivative assets, net	5	6
Derivative liabilities
Derivative liabilities, gross	(8)	(1)
Derivative liability, netting	5	1
Derivative liabilities, net	(3)	0
Interest rate contracts
Derivative liabilities
Derivative liabilities, gross	0	(3)
Derivative liability, netting	0	0
Derivative liabilities, net	0	(3)
Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	2	4
Derivative asset, netting	0	0
Derivative assets, net	2	4
Recurring
Assets
Cash equivalents	21	18
Derivative assets
Derivative asset, netting	(318)	(530)
Derivative assets, net	111	133
Total assets	1,921	1,712
Derivative liabilities
Derivative liability, netting	318	513
Derivative liabilities, net	(142)	(156)
Net Assets (Liabilities) at end of period	1,779	1,556
Net Assets (Liabilities) at end of period, netting	0	(17)
Recurring | DTE Electric
Assets
Cash equivalents	11	10
Derivative assets
Total assets	1,605	1,404
Recurring | Current assets
Derivative assets
Derivative asset, netting	(271)	(461)
Total assets	96	120
Recurring | Current assets | DTE Electric
Derivative assets
Total assets	16	16
Recurring | Noncurrent assets
Derivative assets
Derivative asset, netting	(47)	(69)
Total assets	1,825	1,592
Recurring | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,589	1,388
Recurring | Current liabilities
Derivative liabilities
Derivative liability, netting	271	451
Derivative liabilities, net	(68)	(67)
Recurring | Noncurrent liabilities
Derivative liabilities
Derivative liability, netting	47	62
Derivative liabilities, net	(74)	(89)
Recurring | Cash and cash equivalents
Assets
Cash equivalents	10	3
Recurring | Restricted cash
Assets
Cash equivalents		5
Recurring | Other investments
Assets
Cash equivalents	11	10
Recurring | Other investments | DTE Electric
Assets
Cash equivalents	11	10
Recurring | Natural gas
Derivative assets
Derivative asset, netting	(189)	(277)
Derivative assets, net	64	72
Derivative liabilities
Derivative liability, netting	189	272
Derivative liabilities, net	(108)	(108)
Recurring | Electricity
Derivative assets
Derivative asset, netting	(124)	(252)
Derivative assets, net	40	51
Derivative liabilities
Derivative liability, netting	124	240
Derivative liabilities, net	(31)	(45)
Recurring | Other
Derivative assets
Derivative asset, netting	(5)	(1)
Derivative assets, net	5	6
Derivative liabilities
Derivative liability, netting	5	1
Derivative liabilities, net	(3)	0
Recurring | Interest rate contracts
Derivative liabilities
Derivative liability, netting	0	0
Derivative liabilities, net	0	(3)
Recurring | Foreign currency exchange contracts
Derivative assets
Derivative asset, netting	0	0
Derivative assets, net	2	4
Recurring | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	5	6
Recurring | Cash equivalents
Assets
Nuclear decommissioning trusts	9	5
Other investments	4	4
Recurring | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	9	5
Recurring | Private equity and other
Assets
Nuclear decommissioning trusts	34	20
Recurring | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	34	20
Recurring | Equity securities
Assets
Nuclear decommissioning trusts	990	851
Other investments	130	110
Recurring | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	990	851
Other investments	12	10
Recurring | Fixed income securities
Assets
Nuclear decommissioning trusts	544	502
Other investments	78	69
Recurring | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	544	502
Recurring | Level 1
Assets
Cash equivalents	21	16
Derivative assets
Derivative assets, gross	114	199
Total assets	1,355	1,266
Derivative liabilities
Derivative liabilities, gross	(137)	(197)
Net Assets (Liabilities) at end of period	1,218	1,069
Recurring | Level 1 | DTE Electric
Assets
Cash equivalents	11	8
Derivative assets
Total assets	1,031	886
Recurring | Level 1 | Current assets
Derivative assets
Total assets	130	212
Recurring | Level 1 | Current assets | DTE Electric
Derivative assets
Total assets	11	8
Recurring | Level 1 | Noncurrent assets
Derivative assets
Total assets	1,225	1,054
Recurring | Level 1 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,020	878
Recurring | Level 1 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(123)	(191)
Recurring | Level 1 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(14)	(6)
Recurring | Level 1 | Natural gas
Derivative assets
Derivative assets, gross	109	199
Derivative liabilities
Derivative liabilities, gross	(130)	(197)
Recurring | Level 1 | Electricity
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Other
Derivative assets
Derivative assets, gross	5	0
Derivative liabilities
Derivative liabilities, gross	(7)	0
Recurring | Level 1 | Interest rate contracts
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Recurring | Level 1 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	0	0
Recurring | Level 1 | Cash equivalents
Assets
Nuclear decommissioning trusts	9	5
Other investments	4	4
Recurring | Level 1 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	9	5
Recurring | Level 1 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 1 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 1 | Equity securities
Assets
Nuclear decommissioning trusts	990	851
Other investments	130	110
Recurring | Level 1 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	990	851
Other investments	12	10
Recurring | Level 1 | Fixed income securities
Assets
Nuclear decommissioning trusts	9	12
Other investments	78	69
Recurring | Level 1 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	9	12
Recurring | Level 2
Assets
Cash equivalents	0	2
Derivative assets
Derivative assets, gross	220	338
Total assets	755	830
Derivative liabilities
Derivative liabilities, gross	(200)	(302)
Net Assets (Liabilities) at end of period	555	528
Recurring | Level 2 | DTE Electric
Assets
Cash equivalents	0	2
Derivative assets
Total assets	535	492
Recurring | Level 2 | Current assets
Derivative assets
Total assets	175	273
Recurring | Level 2 | Current assets | DTE Electric
Derivative assets
Total assets	0	2
Recurring | Level 2 | Noncurrent assets
Derivative assets
Total assets	580	557
Recurring | Level 2 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	535	490
Recurring | Level 2 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(163)	(251)
Recurring | Level 2 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(37)	(51)
Recurring | Level 2 | Natural gas
Derivative assets
Derivative assets, gross	90	87
Derivative liabilities
Derivative liabilities, gross	(72)	(71)
Recurring | Level 2 | Electricity
Derivative assets
Derivative assets, gross	128	247
Derivative liabilities
Derivative liabilities, gross	(127)	(227)
Recurring | Level 2 | Other
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	(1)	(1)
Recurring | Level 2 | Interest rate contracts
Derivative liabilities
Derivative liabilities, gross	0	(3)
Recurring | Level 2 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	2	4
Recurring | Level 2 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	0	0
Recurring | Level 2 | Cash equivalents
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Fixed income securities
Assets
Nuclear decommissioning trusts	535	490
Other investments	0	0
Recurring | Level 2 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	535	490
Recurring | Level 3
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	95	126
Total assets	95	126
Derivative liabilities
Derivative liabilities, gross	(123)	(170)
Net Assets (Liabilities) at end of period	(28)	(44)
Recurring | Level 3 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	5	6
Recurring | Level 3 | Current assets
Derivative assets
Total assets	62	96
Recurring | Level 3 | Current assets | DTE Electric
Derivative assets
Total assets	5	6
Recurring | Level 3 | Noncurrent assets
Derivative assets
Total assets	33	30
Recurring | Level 3 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 3 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(53)	(76)
Recurring | Level 3 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(70)	(94)
Recurring | Level 3 | Natural gas
Derivative assets
Derivative assets, gross	54	63
Derivative liabilities
Derivative liabilities, gross	(95)	(112)
Recurring | Level 3 | Electricity
Derivative assets
Derivative assets, gross	36	56
Derivative liabilities
Derivative liabilities, gross	(28)	(58)
Recurring | Level 3 | Other
Derivative assets
Derivative assets, gross	5	7
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Interest rate contracts
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Recurring | Level 3 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	5	6
Recurring | Level 3 | Cash equivalents
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Other
Derivative assets
Total assets	34	20
Derivative liabilities
Net Assets (Liabilities) at end of period	34	20
Recurring | Other | DTE Electric
Derivative assets
Total assets	34	20
Recurring | Other | Noncurrent assets
Derivative assets
Total assets	34	20
Recurring | Other | Noncurrent assets | DTE Electric
Derivative assets
Total assets	34	20
Recurring | Other | Private equity and other
Assets
Nuclear decommissioning trusts	34	20
Recurring | Other | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	$ 34	$ 20

Fair Value (Reconciliation of L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ 9	$ (23)	$ (44)	$ (9)
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	(3)
Total gains (losses):
Included in earnings	2	(9)	42	(102)
Recorded in/Change in fair value recorded in Regulatory liabilities	(3)	(8)	3	6
Purchases, issuances, and settlements
Settlements	(36)	(10)	(29)	58
Net Assets (Liabilities) as of end of period	(28)	(50)	(28)	(50)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(22)	(22)	6	(108)
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	9	15	6	9
Total gains (losses):
Recorded in/Change in fair value recorded in Regulatory liabilities	(3)	(8)	3	6
Purchases, issuances, and settlements
Settlements	(1)	(1)	(4)	(9)
Net Assets (Liabilities) as of end of period	5	6	5	6
The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2019 and 2018 and reflected in DTE Electric's Consolidated Statements of Financial Position	(1)	(2)	5	6
Natural gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(10)	(25)	(49)	(29)
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	(3)
Total gains (losses):
Included in earnings	(35)	(30)	(4)	(128)
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements
Settlements	4	9	12	114
Net Assets (Liabilities) as of end of period	(41)	(46)	(41)	(46)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(36)	(31)	(20)	(109)
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	10	(13)	(2)	12
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses):
Included in earnings	37	21	47	25
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements
Settlements	(39)	(18)	(37)	(47)
Net Assets (Liabilities) as of end of period	8	(10)	8	(10)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	15	10	32	4
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	9	15	7	8
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses):
Included in earnings	0	0	(1)	1
Recorded in/Change in fair value recorded in Regulatory liabilities	(3)	(8)	3	6
Purchases, issuances, and settlements
Settlements	(1)	(1)	(4)	(9)
Net Assets (Liabilities) as of end of period	5	6	5	6
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	$ (1)	$ (1)	$ (6)	$ (3)

Fair Value (Unobservable Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) $ in Millions	Sep. 30, 2019USD ($)$ / MWh$ / MMBTU	Dec. 31, 2018USD ($)$ / MWh$ / MMBTU
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	$ 429	$ 663
Derivative Liabilities	(460)	(669)
Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	95	126
Derivative Liabilities	(123)	(170)
Natural gas
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	253	349
Derivative Liabilities	(297)	(380)
Natural gas | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	54	63
Derivative Liabilities	(95)	(112)
Electricity
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	164	303
Derivative Liabilities	(155)	(285)
Electricity | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	36	56
Derivative Liabilities	$ (28)	$ (58)
Forward basis price | Natural gas | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(1.55)	(2.15)
Forward basis price | Natural gas | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	6.17	5.59
Forward basis price | Natural gas | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(0.09)	(0.10)
Forward basis price | Electricity | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	(13)	(7)
Forward basis price | Electricity | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	7	9
Forward basis price | Electricity | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	0	1

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	$ 178	$ 40
Dividends payable	173	172
Short-term borrowings	724	609
Notes payable — Other, excluding lessee finance leases	27	41
Long-term debt	15,056	13,622
Carrying amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	14	6
Short-term borrowings	382	149
Notes payable — Other, excluding lessee finance leases	23	21
Long-term debt	7,179	6,538
Carrying amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	97	101
Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	0	0
Dividends payable	173	172
Short-term borrowings	0	0
Notes payable — Other, excluding lessee finance leases	0	0
Long-term debt	1,277	1,796
Fair value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	0	0
Short-term borrowings	0	0
Notes payable — Other, excluding lessee finance leases	0	0
Long-term debt	0	0
Fair value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	0	0
Dividends payable	0	0
Short-term borrowings	724	609
Notes payable — Other, excluding lessee finance leases	0	0
Long-term debt	14,216	10,712
Fair value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	0	0
Short-term borrowings	382	149
Notes payable — Other, excluding lessee finance leases	0	0
Long-term debt	7,996	6,552
Fair value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	178	40
Dividends payable	0	0
Short-term borrowings	0	0
Notes payable — Other, excluding lessee finance leases	27	41
Long-term debt	1,138	1,317
Fair value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other, excluding lessor finance leases	14	6
Short-term borrowings	0	0
Notes payable — Other, excluding lessee finance leases	23	21
Long-term debt	176	161
Fair value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 97	$ 101

Fair Value (Fair Value of Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 1,577	$ 1,378
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,577	1,378
DTE Electric | Nuclear decommissioning trust fund
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,577	1,378
DTE Electric | Nuclear decommissioning trust fund | Fermi 2
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,567	1,372
DTE Electric | Nuclear decommissioning trust fund | Fermi 1
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trust fund | Low-level radioactive waste
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 7	$ 3

Fair Value (Gains and Losses an

Fair Value (Gains and Losses and Proceeds from the Sale of Securities by the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 15	$ 10	$ 43	$ 52
Realized losses	(8)	(7)	(25)	(22)
Proceeds from sale of securities	$ 198	$ 194	$ 594	$ 810

Fair Value (Fair Value and Unre

Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 1,577	$ 1,378
Fixed income securities, fair value	544	502
Private equity and other, fair value	34	20
Cash equivalents, fair value	9	5
Unrealized Gains	362	242
Fixed income securities, unrealized gains	27	7
Unrealized Losses	(54)	(87)
Fixed income securities, unrealized losses	(1)	(8)
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	990	851
Unrealized Gains	335	235
Unrealized Losses	$ (53)	$ (79)

Fair Value Fair Value (Fair Val

Fair Value Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Fixed income securities - Nuclear decommissioning trust fund $ in Millions	Sep. 30, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 23
Due after one through five years	98
Due after five through ten years	108
Due after ten years	315
Available-for-sale securities total	$ 544

Fair Value (Details Textuals)

Fair Value (Details Textuals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Equity securities realized gains	$ 3	$ 5	$ 27	$ 4

Financial and Other Derivativ_3

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 429	$ 663
Derivative Liabilities	(460)	(669)
Current derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	346	563
Current derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(339)	(518)
Noncurrent derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	83	100
Noncurrent derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(121)	(151)
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	(3)
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	253	349
Derivative Liabilities	(297)	(380)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	164	303
Derivative Liabilities	(155)	(285)
Other
Derivatives, Fair Value [Line Items]
Derivative Assets	10	7
Derivative Liabilities	(8)	(1)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	2	4
Derivatives designated as hedging instruments | Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	0	(3)
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	429	663
Derivative Liabilities	(460)	(666)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	5	6
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	253	349
Derivative Liabilities	(297)	(380)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	164	303
Derivative Liabilities	(155)	(285)
Derivatives not designated as hedging instruments | Other
Derivatives, Fair Value [Line Items]
Derivative Assets	10	7
Derivative Liabilities	(8)	(1)
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	2	4
Derivative Liabilities	0	0
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 5	$ 6

Financial and Other Derivativ_4

Financial and Other Derivative Instruments (Details Textuals) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$ 2,000,000	$ 4,000,000
Letters of credit received that could be used to offset net derivative assets	6,000,000	$ 8,000,000
Contractual obligation to post collateral in event of downgrade to below investment grade	517,000,000
Derivative net liability position aggregate fair value	364,000,000
Collateral already posted fair value	0
Derivative net asset position, fair value	304,000,000
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	$ 60,000,000

Financial and Other Derivativ_5

Financial and Other Derivative Instruments (Net Cash Collateral Offsetting Arrangements) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral netted against Derivative assets	$ 0	$ (17)
Cash collateral recorded in Accounts receivable	9	10
Cash collateral recorded in Accounts payable	(6)	(6)
Total net cash collateral posted (received)	$ 3	$ (13)

Financial and Other Derivativ_6

Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	$ 429	$ 663
Gross Amounts Offset in the Consolidated Statements of Financial Position	(318)	(530)
Derivative assets, net	111	133
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(460)	(669)
Gross Amounts Offset in the Consolidated Statements of Financial Position	318	513
Derivative liabilities, net	(142)	(156)
Natural gas
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	253	349
Gross Amounts Offset in the Consolidated Statements of Financial Position	(189)	(277)
Derivative assets, net	64	72
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(297)	(380)
Gross Amounts Offset in the Consolidated Statements of Financial Position	189	272
Derivative liabilities, net	(108)	(108)
Electricity
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	164	303
Gross Amounts Offset in the Consolidated Statements of Financial Position	(124)	(252)
Derivative assets, net	40	51
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(155)	(285)
Gross Amounts Offset in the Consolidated Statements of Financial Position	124	240
Derivative liabilities, net	(31)	(45)
Other
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	10	7
Gross Amounts Offset in the Consolidated Statements of Financial Position	(5)	(1)
Derivative assets, net	5	6
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(8)	(1)
Gross Amounts Offset in the Consolidated Statements of Financial Position	5	1
Derivative liabilities, net	(3)	0
Interest rate contracts
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	0	(3)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative liabilities, net	0	(3)
Foreign currency exchange contracts
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	2	4
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative assets, net	$ 2	$ 4

Financial and Other Derivativ_7

Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative Assets
Derivative Assets	$ 429	$ 663
Collateral adjustment	0	(17)
Derivative assets, current	75	102
Derivative assets, noncurrent	36	31
Derivative Liabilities
Derivative Liabilities	(460)	(669)
Derivative liabilities, current	(68)	(67)
Derivative liabilities, noncurrent	(74)	(89)
Current derivative assets
Derivative Assets
Derivative Assets	346	563
Counterparty netting	(271)	(451)
Collateral adjustment	0	(10)
Derivative assets, current	75	102
Noncurrent derivative assets
Derivative Assets
Derivative Assets	83	100
Counterparty netting	(47)	(62)
Collateral adjustment	0	(7)
Derivative assets, noncurrent	36	31
Current derivative liabilities
Derivative Liabilities
Derivative Liabilities	(339)	(518)
Counterparty netting	271	451
Collateral adjustment	0	0
Derivative liabilities, current	(68)	(67)
Noncurrent derivative liabilities
Derivative Liabilities
Derivative Liabilities	(121)	(151)
Counterparty netting	47	62
Collateral adjustment	0	0
Derivative liabilities, noncurrent	$ (74)	$ (89)

Financial and Other Derivativ_8

Financial and Other Derivative Instruments (Effect of Derivatives not Designated as Hedging Instruments on the Consolidated Statement of Operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (8)	$ (11)	$ 5	$ (85)
Natural gas | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(5)	(29)	4	(51)
Natural gas | Fuel, purchased power, and gas — non-utility
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(47)	(6)	(7)	(74)
Electricity | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	54	26	21	37
Other | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(11)	0	(11)	1
Foreign currency exchange contracts | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ 1	$ (2)	$ (2)	$ 2

Financial and Other Derivativ_9

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	9 Months Ended
	Sep. 30, 2019CAD ($)MMBTUMWh
Natural gas (MMBtu)
Derivative [Line Items]
Commodity | MMBTU	2,018,659,087
Electricity (MWh)
Derivative [Line Items]
Commodity | MWh	30,880,332
Foreign currency exchange (CAD)
Derivative [Line Items]
Foreign currency exchange (CAD) | $	$ 79,292,076

Long-Term Debt (Schedule of Iss

Long-Term Debt (Schedule of Issued Debt) (Details)	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
Debt issued	$ 1,450,000,000
DTE Energy | Senior Notes | June 2019 2.60% Senior Notes Maturing 2022
Debt Instrument [Line Items]
Interest rate	2.60%
Debt issued	$ 300,000,000
DTE Energy | Senior Notes | June 2019 3.40% Senior Notes Maturing 2029
Debt Instrument [Line Items]
Interest rate	3.40%
Debt issued	$ 500,000,000
DTE Electric | Mortgage Bonds | February 2019 3.95% Mortgage Bonds Maturing 2049
Debt Instrument [Line Items]
Interest rate	3.95%
Debt issued	$ 650,000,000

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) shares in Thousands	Oct. 01, 2019	Oct. 31, 2019	Sep. 30, 2019	Aug. 31, 2019
Debt Instrument [Line Items]
Debt issued			$ 1,450,000,000
Subsequent event | Stock Purchase Contract, 2016 Series C Equity Units Subject to Mandatory Redemption
Debt Instrument [Line Items]
Shares of common stock issued under stock purchase contracts (in shares)	5,870
Senior Notes | 2016 Series D 1.5% Senior Notes | Subsequent event | DTE Energy
Debt Instrument [Line Items]
Interest rate		1.50%
Securities redeemed at maturity		$ 400,000,000
Senior Notes | Series C, 1.5% RSNs due 2024
Debt Instrument [Line Items]
Debt issued				$ 675,000,000
Interest rate				1.50%
Senior Notes | Series C, Remarketed, 2.529% RSN due 2024 | Subsequent event
Debt Instrument [Line Items]
Interest rate	2.529%
DTE Gas | Mortgage Bonds | October 2019 2.95% First Mortgage Bonds Maturing 2029 | Subsequent event
Debt Instrument [Line Items]
Debt issued		$ 140,000,000
Interest rate		2.95%
DTE Gas | Mortgage Bonds | October 2019 3.72% First Mortgage Bonds Maturing 2049 | Subsequent event
Debt Instrument [Line Items]
Debt issued		$ 140,000,000
Interest rate		3.72%
DTE Gas | Senior Notes | 2004 Series E 5.0% Senior Notes | Subsequent event
Debt Instrument [Line Items]
Interest rate		5.00%
Securities redeemed at maturity		$ 120,000,000

Short-Term Credit Arrangement_3

Short-Term Credit Arrangements and Borrowings (Details Textuals)	Sep. 30, 2019USD ($)	Aug. 31, 2019USD ($)	Jul. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 2,560,000,000
Other outstanding letters of credit	915,000,000
Letter of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	191,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	110,000,000
DTE Electric
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 500,000,000
Ratio of indebtedness to net capital	0.52
Other outstanding letters of credit	$ 382,000,000
DTE Electric | Letter of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	0
DTE Electric | Unsecured letter of credit facility, expiring in August 2021 | Letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Gas
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 300,000,000
Ratio of indebtedness to net capital	0.46
Other outstanding letters of credit	$ 232,000,000
DTE Gas | Letter of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	0
DTE Gas | Unsecured letter of credit facility, expiring in August 2021 | Letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 1,760,000,000
Ratio of indebtedness to net capital	0.57
Other outstanding letters of credit	$ 301,000,000
DTE Energy | Letter of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	191,000,000
DTE Energy | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	100,000,000
Maximum additional margin financing	50,000,000
Amount outstanding	94,000,000			$ 93,000,000
DTE Energy | Demand financing agreement plus letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	150,000,000
DTE Energy | Unsecured letter of credit facility, expiring in September 2019 | Letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity			$ 70,000,000
DTE Energy | Unsecured letter of credit facility, expiring in August 2021 | Letter of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	110,000,000	$ 110,000,000
DTE Energy | Other outstanding letters of credit | Letter of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	$ 9,000,000
Maximum
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.65

Short-Term Credit Arrangement_4

Short-Term Credit Arrangements and Borrowings (Details) - USD ($)	Sep. 30, 2019	Aug. 31, 2019
Availability under combined facilities
Maximum borrowing capacity	$ 2,560,000,000
Amounts outstanding	915,000,000
Net availability	1,645,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Amounts outstanding	382,000,000
Net availability	118,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	232,000,000
Net availability	68,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,760,000,000
Amounts outstanding	301,000,000
Net availability	1,459,000,000
Letter of credit
Availability under combined facilities
Amounts outstanding	191,000,000
Letter of credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letter of credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letter of credit | DTE Energy
Availability under combined facilities
Amounts outstanding	191,000,000
Letter of credit | Unsecured letter of credit facility, expiring in February 2021
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Letter of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Letter of credit | Unsecured letter of credit facility, expiring in August 2021
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Letter of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	110,000,000	$ 110,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024
Availability under combined facilities
Maximum borrowing capacity	2,300,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,500,000,000
Commercial paper issuances
Availability under combined facilities
Amounts outstanding	724,000,000
Commercial paper issuances | DTE Electric
Availability under combined facilities
Amounts outstanding	382,000,000
Commercial paper issuances | DTE Gas
Availability under combined facilities
Amounts outstanding	232,000,000
Commercial paper issuances | DTE Energy
Availability under combined facilities
Amounts outstanding	$ 110,000,000

Leases Leases (Details Textuals

Leases Leases (Details Textuals) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)agreement	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Lessee, Lease, Description [Line Items]
Term of finance lease contract	20 years	20 years
Finance lease contract, renewal option extension term	5 years	5 years
Percent ownership interest in Vector Pipeline	40.00%	40.00%
Depreciation expense associated with property under operating leases	$ 7	$ 20
Interest income recognized under finance leases	$ 2	$ 4
Contingent rental revenues			$ 107	$ 91	$ 101
Pipeline System Lease
Lessee, Lease, Description [Line Items]
Percent ownership interest in Vector Pipeline			40.00%
Lessor capital lease renewal terms			5 years
Number of energy services agreements | agreement			2
Minimum
Lessee, Lease, Description [Line Items]
Lease terms		2 years
Term of operating lease contracts	3 years	3 years
Maximum
Lessee, Lease, Description [Line Items]
Lease terms		40 years
Term of operating lease contracts	24 years	24 years
DTE Electric | Minimum
Lessee, Lease, Description [Line Items]
Lease terms		2 years
DTE Electric | Maximum
Lessee, Lease, Description [Line Items]
Lease terms		40 years

Leases (Components of Lease Cos

Leases (Components of Lease Cost) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 10	$ 31
Finance lease cost:
Amortization of right-of-use assets	0	3
Interest of lease liabilities	0	0
Total finance lease cost	0	3
Variable lease cost	2	8
Short-term lease cost	2	7
Total lease cost	14	49
DTE Electric
Lessee, Lease, Description [Line Items]
Operating lease cost	5	13
Finance lease cost:
Amortization of right-of-use assets	0	3
Interest of lease liabilities	0	0
Total finance lease cost	0	3
Variable lease cost	0	0
Short-term lease cost	1	2
Total lease cost	$ 6	$ 18

Leases (Other Information) (Det

Leases (Other Information) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Cash paid for amounts included in the measurement of these liabilities:
Operating cash flows from finance leases	$ 4
Operating cash flows from operating leases	30
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 37
Weighted Average Remaining Lease Term
Operating leases	9 years 8 months 12 days
Finance leases	2 years 3 months 18 days
Weighted Average Discount Rate
Operating leases	3.70%
Finance leases	3.10%
DTE Electric
Cash paid for amounts included in the measurement of these liabilities:
Operating cash flows from finance leases	$ 4
Operating cash flows from operating leases	11
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 2
Weighted Average Remaining Lease Term
Operating leases	10 years 7 months 6 days
Finance leases	2 years 3 months 18 days
Weighted Average Discount Rate
Operating leases	3.70%
Finance leases	3.10%

Leases (Future Minimum Lease Pa

Leases (Future Minimum Lease Payments - Topic 842) (Details) $ in Millions	Sep. 30, 2019USD ($)
Operating Leases
2019	$ 10
2020	35
2021	26
2022	19
2023	16
2024 and thereafter	62
Total future minimum lease payments	168
Imputed interest	(30)
Total	138
Finance Leases
2019	1
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	8
Imputed interest	0
Total	8
DTE Electric
Operating Leases
2019	4
2020	13
2021	11
2022	7
2023	6
2024 and thereafter	30
Total future minimum lease payments	71
Imputed interest	(13)
Total	58
Finance Leases
2019	1
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	8
Imputed interest	0
Total	$ 8

Leases (Finance Leases Reported

Leases (Finance Leases Reported on Consolidated Statements of Financial Position) (Details) $ in Millions	Sep. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Right-of-use assets, within Property, plant, and equipment, net	$ 8
Current lease liabilities, within Current Liabilities — Other	3
DTE Electric
Lessee, Lease, Description [Line Items]
Right-of-use assets, within Property, plant, and equipment, net	8
Current lease liabilities, within Current Liabilities — Other	$ 3

Leases (Future Minimum Lease _2

Leases (Future Minimum Lease Payments for Operating Leases - Topic 840) (Details) $ in Millions	Dec. 31, 2018USD ($)
Lessee, Lease, Description [Line Items]
2019	$ 42
2020	30
2021	18
2022	11
2023	8
2024 and thereafter	45
Total future minimum lease payments	154
DTE Electric
Lessee, Lease, Description [Line Items]
2019	17
2020	12
2021	10
2022	7
2023	5
2024 and thereafter	29
Total future minimum lease payments	$ 80

Leases (Lease Income Associated

Leases (Lease Income Associated with Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Fixed payments	$ 17	$ 51
Variable payments	40	92
Total lease income under operating leases	$ 57	$ 143

Leases (Minimum Future Rental R

Leases (Minimum Future Rental Revenues under Operating Leases) (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
2019	$ 16
2020	66
2021	64
2022	22
2023	22
2024 and thereafter	216
Total minimum future rental revenues under operating leases	$ 406

Leases (Property under Operatin

Leases (Property under Operating Leases - Topic 842) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Gross property under operating leases	$ 33,473	$ 31,810
Accumulated amortization of property under operating leases	9,715	$ 10,160
Property Under Operating Leases
Lessor, Lease, Description [Line Items]
Gross property under operating leases	444
Accumulated amortization of property under operating leases	$ 166

Leases (Components of Net Inves

Leases (Components of Net Investment in Finance Leases) (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
2019	$ 3
2020	9
2021	0
2022	0
2023	0
2024 and thereafter	1
Total minimum future lease receipts	13
Residual value of leased pipeline	40
Less unearned income	6
Net investment in finance lease	47
Less current portion	5
Net investment in finance lease, noncurrent	$ 42

Leases (Future Rental Revenues

Leases (Future Rental Revenues under Operating Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 66
2020	66
2021	64
2022	20
2023	20
2024 and thereafter	196
Total minimum future rental revenues under non-cancelable operating leases	$ 432

Leases (Net Investment in Capit

Leases (Net Investment in Capital Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 10
2020	9
2021	0
2022	0
2023	0
2024 and thereafter	1
Total minimum future lease receipts	20
Residual value of leased pipeline	40
Less unearned income	9
Net investment in capital lease	51
Less current portion	5
Capital lease, noncurrent	$ 46

Leases (Property under Operat_2

Leases (Property under Operating Leases - Topic 840) (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
Gross property under operating leases	$ 447
Accumulated amortization of property under operating leases	$ 148

Commitments and Contingencies (

Commitments and Contingencies (Details Textuals)	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)employeeplantsitefacilityNOV	Dec. 31, 2018USD ($)	Jul. 31, 2019CAD ($)	Jul. 31, 2009plant
Loss Contingencies [Line Items]
Estimated utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees	$ 5,900,000,000
Long-lived assets used in producing electric output for sale	$ 23,758,000,000	$ 21,650,000,000
Power and Industrial Projects
Loss Contingencies [Line Items]
Number of generating plants operated with ownership interest held | plant	5
Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee	5,200
Vector | Revolving Term Credit Facility
Loss Contingencies [Line Items]
Revolving term credit facility amount			$ 70,000,000
Maximum potential payments under line of credit	$ 53,000,000
Pacific Gas and Electric Corporation | Power and Industrial Projects
Loss Contingencies [Line Items]
Long-lived assets used in producing electric output for sale	102,000,000
Equity investments, including note receivable	$ 72,000,000
Impairment loss		0
Other than temporary decline in equity investments		0
Synthetic fuel
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations	90 days
Maximum potential liability	$ 400,000,000
Reduced emissions fuel guarantees
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations	90 days
Maximum potential liability	$ 491,000,000
NEXUS pipeline | DTE Gas
Loss Contingencies [Line Items]
Maximum potential liability	$ 242,000,000
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements	2 months
NEXUS pipeline | Texas Eastern Transmission, LP
Loss Contingencies [Line Items]
Maximum potential liability	$ 377,000,000
Percentage of payment obligations due	50.00%
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements	2 months
NEXUS pipeline | Vector
Loss Contingencies [Line Items]
Maximum potential liability	$ 7,000,000
Percentage of payment obligations due	50.00%
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements	15 years
Other guarantees
Loss Contingencies [Line Items]
Maximum potential liability	$ 56,000,000
Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding	$ 108,000,000
Reduction of Carbon Emissions by Early 2020s
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage	32.00%
Reduction of Carbon Emissions by 2030
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage	50.00%
Reduction of Carbon Emissions by 2040
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage	80.00%
DTE Electric
Loss Contingencies [Line Items]
Number of power plants in violation | plant				5
Number of NOVs/FOVs | NOV	2
Environmental capital expenditures through prior year end		2,400,000,000
Number of former MGP sites | site	3
Accrued for remediation	$ 8,000,000	7,000,000
Number of permitted engineered ash storage facilities owned | facility	3
Estimated utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees	$ 2,200,000,000
Long-lived assets used in producing electric output for sale	$ 17,220,000,000	15,437,000,000
DTE Electric | Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee	2,800
DTE Electric | Reduction of Carbon Emissions by 2050
Loss Contingencies [Line Items]
Goal of net carbon emissions, percentage	0.00%
DTE Gas
Loss Contingencies [Line Items]
Number of former MGP sites | site	14
Accrued for remediation	$ 25,000,000	$ 25,000,000
Amortization period (in years)	10 years
DTE Gas | NEXUS pipeline | DTE Gas
Loss Contingencies [Line Items]
Percentage of payment obligations due	50.00%
DTE Gas | Clean up completed and site closed
Loss Contingencies [Line Items]
Number of former MGP sites | site	8
DTE Gas | Partial closure complete
Loss Contingencies [Line Items]
Number of former MGP sites | site	4
NEXUS | NEXUS pipeline | DTE Gas
Loss Contingencies [Line Items]
Agreement term	15 years
NEXUS | NEXUS pipeline | Texas Eastern Transmission, LP
Loss Contingencies [Line Items]
Agreement term	15 years
NEXUS | NEXUS pipeline | Vector
Loss Contingencies [Line Items]
Agreement term	15 years

Retirement Benefits and Trust_3

Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 21	$ 24	$ 63	$ 74
Interest cost	55	51	164	151
Expected return on plan assets	(82)	(82)	(244)	(247)
Amortization of net actuarial loss	33	43	99	132
Amortization of prior service credit	0	0	0	0
Net periodic benefit cost (credit)	27	36	82	110
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	6	16	20
Interest cost	18	18	53	52
Expected return on plan assets	(30)	(36)	(92)	(107)
Amortization of net actuarial loss	3	3	9	8
Amortization of prior service credit	(3)	0	(7)	0
Net periodic benefit cost (credit)	(7)	(9)	(21)	(27)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	5	12	15
Interest cost	13	13	40	40
Expected return on plan assets	(21)	(25)	(63)	(74)
Amortization of net actuarial loss	1	3	3	7
Amortization of prior service credit	(1)	0	(5)	0
Net periodic benefit cost (credit)	$ (4)	$ (4)	$ (13)	$ (12)

Retirement Benefits and Trust_4

Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Cash contributions made by employer				$ 50,000,000
Additional contributions anticipated, remainder of fiscal year		$ 0		0
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Additional contributions anticipated, remainder of fiscal year		0		0
DTE Electric | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pension cost	$ 100,000,000	$ 23,000,000	$ 30,000,000	$ 68,000,000	$ 90,000,000

Retirement Benefits and Trust_5

Retirement Benefits and Trusteed Assets - VEBA Contributions (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 05, 2019	Mar. 31, 2019	Mar. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Amount		$ 100	$ 175
Pension Benefits
Defined Contribution Plan Disclosure [Line Items]
Number of Shares (in shares)	814,597
Price per Share (in dollars per share)	$ 122.76
Amount	$ 100

Segment and Related Informati_3

Segment and Related Information (Details Textuals) customer in Millions	Sep. 30, 2019customer
Segment Reporting [Abstract]
Number of electric utility customers	2.2
Number of gas utility customers	1.3

Segment and Related Informati_4

Segment and Related Information (Financial Data - Inter-segment Billing) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ (3,119)	$ (3,550)	$ (9,521)	$ (10,462)
Electric
Segment Reporting Information [Line Items]
Revenues	(1,520)	(1,521)	(3,945)	(4,002)
Gas
Segment Reporting Information [Line Items]
Revenues	(155)	(164)	(1,043)	(969)
Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Revenues	(126)	(122)	(363)	(363)
Power and Industrial Projects
Segment Reporting Information [Line Items]
Revenues	(406)	(612)	(1,196)	(1,717)
Energy Trading
Segment Reporting Information [Line Items]
Revenues	(1,105)	(1,332)	(3,519)	(3,994)
Reconciliation and Eliminations
Segment Reporting Information [Line Items]
Revenues	195	201	548	585
Reconciliation and Eliminations | Electric
Segment Reporting Information [Line Items]
Revenues	16	13	43	39
Reconciliation and Eliminations | Gas
Segment Reporting Information [Line Items]
Revenues	3	3	8	9
Reconciliation and Eliminations | Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Revenues	11	7	17	29
Reconciliation and Eliminations | Power and Industrial Projects
Segment Reporting Information [Line Items]
Revenues	160	171	462	488
Reconciliation and Eliminations | Energy Trading
Segment Reporting Information [Line Items]
Revenues	4	6	16	18
Reconciliation and Eliminations | Corporate and Other
Segment Reporting Information [Line Items]
Revenues	$ 1	$ 1	$ 2	$ 2

Segment and Related Informati_5

Segment and Related Information (Financial Data - Operating Revenues including Inter-segment Revenues) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	$ 1,656	$ 1,669	$ 4,937	$ 4,923
Operating Revenues — Non-utility operations	1,463	1,881	4,584	5,539
Operating Revenues	3,119	3,550	9,521	10,462
Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	(195)	(201)	(548)	(585)
Operating Revenues	(195)	(201)	(548)	(585)
Electric
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,520	1,521	3,945	4,002
Electric | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	1,520	1,521	3,945	4,002
Electric | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(16)	(13)	(43)	(39)
Gas
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	155	164	1,043	969
Gas | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	155	164	1,043	969
Gas | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(3)	(3)	(8)	(9)
Gas Storage and Pipelines
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	126	122	363	363
Gas Storage and Pipelines | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	126	122	363	363
Gas Storage and Pipelines | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(11)	(7)	(17)	(29)
Power and Industrial Projects
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	406	612	1,196	1,717
Power and Industrial Projects | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	406	612	1,196	1,717
Power and Industrial Projects | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(160)	(171)	(462)	(488)
Energy Trading
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,105	1,332	3,519	3,994
Energy Trading | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	1,105	1,332	3,519	3,994
Energy Trading | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(4)	(6)	(16)	(18)
Corporate and Other | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	2	0	3	2
Corporate and Other | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	$ (1)	$ (1)	$ (2)	$ (2)

Segment and Related Informati_6

Segment and Related Information (Financial Data - Net Income (Loss) Attributable to DTE Energy by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ 319	$ 334	$ 902	$ 929
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	307	305	587	608
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	(38)	(30)	121	88
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	60	66	158	188
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	49	58	104	146
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	(14)	(13)	12	13
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ (45)	$ (52)	$ (80)	$ (114)

Subsequent Events (Details Text

Subsequent Events (Details Textuals) - USD ($) $ in Millions	1 Months Ended	6 Months Ended	9 Months Ended		13 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020
Subsequent Event [Line Items]
Estimated purchase price			$ 174	$ 0
Subsequent Event | Forecast | M5 Louisiana Gathering, LLC
Subsequent Event [Line Items]
Percent of assets acquired	100.00%
Estimated purchase price	$ 2,250	$ 400			$ 2,650